Sprinter-Forum    
 

Go Back   Sprinter-Forum > T1N Sprinters > T1N Write-Ups

T1N Write-Ups Help other T1N owners by posting your experience working on your Sprinter.


Reply
 
Thread Tools Display Modes
Old 07-27-2009, 10:43 PM   #1
Aqua Puttana
Poly - Thread Finder
 
Aqua Puttana's Avatar
 
Join Date: Apr 2008
Location: The Falls of Niagara, USA
Posts: 10,751
Thanks: 4,460
Thanked 4,593 Times in 3,051 Posts
Default LHM limp home mode possible causes

lack loss of, no power on hills engine sluggish

Limp Home Mode (LHM) Possible Causes

Limp Home Mode or Limp-in is an operating condition set by the Sprinter computer(s). Technicians may refer to the vehicle computer as the ECU Engine Control Unit, ECM engine control module, or PCM power-train control module. The ECM or TCM transmission control module both have the capability of setting a LHM state. LHM limp home mode is a programmed response for the computer recognizing abnormal operation of your engine/drive-train. The intent is that it limits the power available and therefore will allow you to operate the engine and keep driving, but limit any damage to your engine and drive train.

There are various levels of LHM possible. The most severe is the transmission limited to one forward gear (usually 2nd gear) and reverse, with engine power reduced. LHM is not really a symptom as such, it is more a normal pre-programmed response to the recognized problem. The MIL Malfunction Indicator Light, or sometimes called the CEL Check Engine Light may or may not be lit when the computer calls for LHM.

Please read this: It is important to note that all loss of power situations are not necessarily LHM set by the computer. Regular old problems like a plugged fuel filter, dirty air filter, mechanical turbo control linkage failures, plugged exhaust system, etc. may also cause a lack of power which is not computer set/related. The computer only sets LHM if it becomes aware of a problem, sometimes the sensors don't notice so it just doesn't know. It would be so much easier if MB included a "LHM Set" dash light indicator.

Any diagnosing of why your Sprinter went into LHM needs to include reading the trouble codes available. It very well may require using a dealer computer scan tool. That is a DRBIII or DAD for T1N model NAFTA Sprinters (2006 and older).

Although this LHM info is posted in a T1N section much of it applies to both the T1N and NCV3. Please note that the model specific information is intermixed.

20120103 edit:
My personal method of determining whether there is a computer set LHM.

Sometimes the computer isn't involved with low power situations. The test I feel applies is this:

Lower forms of LHM.
After having not made any repairs or alterations, if your normal operation and power returns after a simple shutdown and restart then whether you have an MIL (aka CEL) lit or not, the computer was involved in limiting the power. In most cases the symptoms will eventually return.

Additional info:

More severe forms of LHM.
If a shutdown/restart doesn't return operation to normal and you have a MIL (aka CEL) lit then the computer is likely set an LHM which requires clearing the codes with a scan tool.

Limited to one forward gear (likely 2nd) and reverse gear.
The most severe level of LHM. This form of LHM is often related to transmission problems. This most often requires reset by a scan tool capable of communication with the Transmission Control Module TCM.

These are some known conditions that may cause the ECM to set LHM.

Turbo Boost Pressures abnormal

Any time the turbo boost, or the Mass Air calculated value, is not in a range that the ECU considers normal it may set LHM. Some possible turbo boost leak areas are:
In 2004 - 2006 NAFTA Models - Turbo resonator failure. Typically a seam cracks. One indication of leakage is oil being found on that cracked seam.

In all models - splits in the turbo outlet hoses and loose clamps are a possibility. Cracked Charge Air Coolers have been reported. Charge Air Cooler cracks don't seem to be a common failure, but should be inspected. There is a mechanical turbo blade positioner on pre-2004 OM612 engines and an electrical positioner on the 2004 - 2006 OM647 engines. Anything that may allow turbo air to leak, or anything that reduces turbo air flow to the manifold can be a problem.

Turbo boost system leaks should be repaired in a timely manner. The turbo may be set to full output to try and supply proper intake pressures if there is a leak. Operating at full output all the time may reduce the service life of the turbo.

EGR Exhaust Gas Recirculating Problems

The EGR has been known to cause an LHM response. On pre-2004 OM612 engines an EGR cleaning may address the problem. Post 2003 model EGR units do not seem to need regular cleaning. There is recent threads that indicate post OM612 EGR valves will respond to DIY cleaning if it is discovered that the valve doesn't snap back closed freely. DO NOT REMOVE THE EGR body SECURITY SCREWS WITH THE LITTLE REJECTION NUB IN THE TORX HEAD.


After I wrote the above introduction rather than re-inventing the wheel I contacted JD Caples to see if he had any input. The following is what he contributed. Many thanks to Jon for his efforts and input. I just cut and pasted, so it may be a bit disjointed. Additional LHM cause information posted by others is encouraged. Hope this does some good. vic

Jon's Input:

Transmission Sensor Readings (whether an actual physical condition or faulty sensor reading)
From Andy Bittenbinder:
Limp home mode is typically triggered by overspeed indications from
the internal transmission input speed sensors, engine overspeed or
improper gear ratio faults. You will likely find TCM DTCs related to
these faults. Cause can be electrical, control unit or transmission
related. Doktor A
More from Andy Bittenbinder:
The TCM(transmission control module) is able to signal the illumination of
a MIL(malfunction indicator lamp)which we see in the instrument
cluster as the small engine/trans(drivetrain) pictogragh. It does this
by communicating with the ECU(engine control unit) to trigger that
lamp. The TCM stores its own failure codes(DTCs) which can then be
accessed by technicians. It can recognize many misc. elect. problems
and some hydraulic problems.
First a few words regarding limp-home/shut down modes. Some (minor)
DTCs(failure codes) will allow the trans to resume business as usual
when problems go away on their own. More serious anomalies will shut
down all the internal solenoids and default to whatever gear you
happen to be in at the time. After you cycle the ign. key (or shift
into park) it will then go into a limp-home mode which is (usually)
2nd gear and reverse and a shut off of the TCC(torque converter
clutch). Typically a max. of about 3 cycles of the key will allow a
"temporary reset" to quasi-normal operation and after that, limp-home
will be permanent until the dealer clears the codes. Some failures
will not shut down all internal control solenoids. If internal
slippage is detected it may default to 3rd gear operation(in
limp-home). The transmission can even become totally disabled by
defaulting to neutral(!). Engine overrev could trigger that mode.
How does the TCM know when fluid levels are low? Or more
importantly, low enough to cause possible damage? The TCM monitors the
speed of the 2 internal drive elements. It also monitors output
shaft speed(I seem to recall it has no dedicated sensor for this
funtion but uses ABS or some other external signal). Anyway, by
monitoring these rotational speeds it can recognize (and calculate)
SLIPPAGE. In 2nd, 3rd, and 4th, for instance, the elements should be
spinning at same speeds. It probably will recognize it before you can
and then trigger the MIL and limp-home. Permanent damage then depends
on how far you drive under these conditions. Moral of the story-If
driving and engine-trans MIL lights and limp symptoms appear-STOP and
at least look inside/underneath for signs of the obvious-such as
leakage. Carry a trans dipstick and extra fluid if you're prone to
driving far from civilization. Oh, and a postscript-just to complicate
things- not all limp-homes of 2nd gear and reverse involve
transmission anomalies! For instance a failure of communication
between control units (via the CAN bus) will trigger that same
limp-home. If the TCM can't talk to the ABS control unit your going
home in 2nd gear(that is-after those 3 ign. key cycles). Andy
__________________
NAS (N. American Spec) aka NAFTA 2004 OM647 140 2500 Std Roof >271,000 mi. Paint=Arctic Whitewash, DAD
"My opinion and worth everything you'll never pay for it." is expressly implied.
Keeping me on topic will be as successful as herding cats.
Anyone can hold the helm when the sea is calm. Publilius Syrus
"There are only 10 types of people in the world: Those who understand binary, and those who don't." HaWiiLuVeR
Some people have 10 years experience, others just 1 year 10 times.

Last edited by Aqua Puttana; 11-25-2013 at 01:52 AM.
Aqua Puttana is offline   Reply With Quote
The Following 21 Users Say Thank You to Aqua Puttana For This Useful Post:
Buckskinner (03-21-2013), cajundjb (07-28-2009), calbiker (11-10-2012), CJPJ (07-09-2013), djjeffa (04-23-2014), flynryan115 (07-14-2013), fredbail (09-21-2013), hayduke (06-08-2011), johnpfree (08-02-2011), kilsco (01-24-2012), KL2BE (06-23-2010), leopena (01-24-2012), parkerbarrow (02-17-2010), ronsuek (10-25-2010), seans (09-09-2010), sterling (05-04-2012), tekcomp (06-13-2010), traveltech (10-16-2013), tymr287 (08-02-2013), Wildmonkey (12-02-2012), williamwyatt (06-22-2010)
Old 07-27-2009, 10:44 PM   #2
Aqua Puttana
Poly - Thread Finder
 
Aqua Puttana's Avatar
 
Join Date: Apr 2008
Location: The Falls of Niagara, USA
Posts: 10,751
Thanks: 4,460
Thanked 4,593 Times in 3,051 Posts
Default Re: LHM limp home mode possible causes

More of Jon's input. (I ran out of character space in the first post.)

Overheated Fuel
The fuel system is a fluid circuit starting at the fuel tank, forward to the filter and injector pump, then to the common rail. Fuel which is unneeded for combustion will be returned to the tank though a low pressure return system that MB refers to as the "leak oil line." Fuel is heated on its path to and from the engine compartment.
The ECM will reduce engine power (limp) to prevent overheating of fuel.
A scan tool is able to read the fuel temperature information received by the ECU to confirm the source of the problem is a sensor crying wolf, or an actual temperature issue.
Crankshaft Position Sensor (CPS) (recall info description)
Details: ON CERTAIN UTILITY VANS, THE CRANKSHAFT SENSOR IN CERTAIN
DIESEL ENGINES COULD FAIL DUE TO SEPARATION OF BOND WIRES FROM THE
LEAD FRAME IN THE SENSOR. THIS RESULTS IN AN INTERRUPTION IN THE
ELECTRICAL CONNECTION IN THE CHIP HOUSING OF THE SENSOR.

Consequence: WHEN THIS HAPPENS, THE VEHICLES MAY LOSE POWER RATHER
THAN ENTER A LIMP-HOME MODE. IN ADDITION, THE VEHICLE CANNOT BE
RESTARTED AFTER FAILURE OF THE ELECTRICAL CONNECTION IN THE SENSOR,
INCREASING THE RISK OF A CRASH.

Corrective Action: DEALERS WILL REPLACE THE CRANKSHAFT SENSORS. THE
RECALL IS EXPECTED TO BEGIN DURING FEBRUARY 2008. OWNERS MAY CONTACT
SPRINTER AT 1-843-695-5000.

NOTE: The Crankshaft Position Sensor (CPS) recall applies ONLY to 2007 Sprinters and even then not all of that year.
More info can be found here:
http://sprinter-source.com/forum/showthread.php?t=7761

Ambient Air Temperature Sensor

This sensor measures the outside air temp. It's used to "verify" the air intake sensor reading.
If the Ambient Air Temperature Sensor is reading someting like 120 degrees F, when it's actually 50 degrees LHM can be unjustifiably triggered when it doesn't agree with the engine air temp.
The EGR Back Pressure Sensor
The EGR back pressure sensor is located in the exhaust stream next to the EGR bypass valve. The sensor determines the exhaust pressure before the catalytic converter. The ECM uses the EGR back pressure sensor for engine protection and exhaust gas turbocharger protection.
To prevent damage to the turbocharger from overheating and/or overspeeding, the ECM monitors the exhaust pressure upstream of the turbocharger. At high exhaust backpressures, the speed of the turbocharger drops and consequently the boost pressure drops. The ECM adjusts the guide vanes in the turbocharger to regulate the boost pressure.
WARNING: If the exhaust back pressure is too high, the ECM switches to limp-in mode to protect the turbocharger. The limp-in mode can only be reset by restarting the engine.
Accelerator Pedal Position
If there is a fault detected with the accelerator pedal position sensor, the ECM will set the engine speed at 1100 RPM.


Transmission Control Module
EMERGENCY RUNNING FUNCTION
In order to ensure a safe driving state and to prevent damage to the automatic transmission, the TCM control module switches to limp-home mode in the event of critical faults. A diagnostic trouble code (DTC) assigned to the fault is stored in memory. All solenoid and regulating valves are thus de-energized.
The net effect is:
The last engaged gear remains engaged.
The modulating pressure and shift pressures rise to the maximum levels.
The torque converter lockup clutch is deactivated.
In order to preserve the operability of the vehicle to some extent, the hydraulic control can be used to engage 2nd gear or reverse using the following procedure:
Stop the vehicle.
Move selector lever to "P".
Switch off engine.
Wait at least 10 seconds.
Start engine.
Move selector lever to D: 2nd gear.
Move selector lever to R: Reverse gear.
The limp-home function remains active until the DTC is rectified or the stored DTC is erased with the appropriate scan tool. Sporadic faults can be reset via ignition OFF/ON.
0228-ELECTRONIC THROTTLE CONTROL SYSTEM - ICE BLOCKAGE.

When Monitored:
Ignition on.
Set Condition:
The ECM recognizes the Throttle plate is stuck during extremely cold Ambient Temperature operation. The throttle plate goes through a de-icing procedure. If the throttle blade still doesn't move this fault sets. The MIL will not illuminate. ETC light will illuminate. The vehicle will be in Limp home condition, limiting rpm and vehicle speed.



Possible Causes

THROTTLE PLATE FROZEN

Diagnostic Test
1. THROTTLE BODY INSPECTION

Ignition on, engine not running.
With a scan tool, View DTCs and record the related Freeze Frame data.
NOTE: This DTC sets in extreme cold Ambient Temperatures with the throttle plate stuck by the time the vehicle gets to the dealership the condition may be corrected.
NOTE: Diagnose any other DTCs that may also be set before continuing.

Turn the ignition off.
Remove the Air Cleaner Assembly from the Throttle Body.
Check for any signs of a foreign material (ice or dirt) on the Throttle Plate or in the bore causing the Throttle Plate to stick.

BOOST PRESSURE SENSOR

If the boost pressure sensor fails, the ECM records a DTC into memory and continues to operate the engine in one of the three limp-in modes. When the ECM is operating in this mode, a loss of power will be present, as if the turbocharger was not operating. The best method for diagnosing faults with the boost pressure sensor is with a diagnostic scan tool.
Refer to On-Board Diagnostics in Emissions Control System for a list of Diagnostic Trouble Codes (DTC's) for certain fuel system components.
__________________
NAS (N. American Spec) aka NAFTA 2004 OM647 140 2500 Std Roof >271,000 mi. Paint=Arctic Whitewash, DAD
"My opinion and worth everything you'll never pay for it." is expressly implied.
Keeping me on topic will be as successful as herding cats.
Anyone can hold the helm when the sea is calm. Publilius Syrus
"There are only 10 types of people in the world: Those who understand binary, and those who don't." HaWiiLuVeR
Some people have 10 years experience, others just 1 year 10 times.

Last edited by Aqua Puttana; 01-03-2013 at 02:24 PM.
Aqua Puttana is offline   Reply With Quote
The Following 8 Users Say Thank You to Aqua Puttana For This Useful Post:
Buckskinner (03-21-2013), cajundjb (07-28-2009), dronsin (04-07-2010), FalconerTom (07-02-2012), flynryan115 (07-14-2013), leopena (01-24-2012), puzo_ter (12-19-2009), ronsuek (10-25-2010)
Old 07-28-2009, 04:21 AM   #3
Aqua Puttana
Poly - Thread Finder
 
Aqua Puttana's Avatar
 
Join Date: Apr 2008
Location: The Falls of Niagara, USA
Posts: 10,751
Thanks: 4,460
Thanked 4,593 Times in 3,051 Posts
Default Re: LHM limp home mode possible causes

Doktor A references LHM in this post (thanks yet again Andy):

Resonator replaced, still not right
http://sprinter-source.com/forum/showthread.php?t=7159
__________________
NAS (N. American Spec) aka NAFTA 2004 OM647 140 2500 Std Roof >271,000 mi. Paint=Arctic Whitewash, DAD
"My opinion and worth everything you'll never pay for it." is expressly implied.
Keeping me on topic will be as successful as herding cats.
Anyone can hold the helm when the sea is calm. Publilius Syrus
"There are only 10 types of people in the world: Those who understand binary, and those who don't." HaWiiLuVeR
Some people have 10 years experience, others just 1 year 10 times.

Last edited by Aqua Puttana; 04-21-2010 at 01:27 AM.
Aqua Puttana is offline   Reply With Quote
The Following User Says Thank You to Aqua Puttana For This Useful Post:
flynryan115 (07-14-2013)
Old 07-29-2009, 01:05 PM   #4
Aqua Puttana
Poly - Thread Finder
 
Aqua Puttana's Avatar
 
Join Date: Apr 2008
Location: The Falls of Niagara, USA
Posts: 10,751
Thanks: 4,460
Thanked 4,593 Times in 3,051 Posts
Default Re: LHM limp home mode possible causes

Another post that may be related to LHM. STP57 does a good job describing the operating conditions as "I experienced a substantial loss of power. I was able to drive it home, it just didn't have any passing speed & it never got over 65 mph." Thanks to STP57 for that description. I'm certain it will help others identify the LHM computer setting. That said, it remains to be seen whether STP57's problem is just a fuel related issue or an actual Limp Home Mode setting condition.

Link to the post is here:
Reset engine light?
http://sprinter-source.com/forum/showthread.php?t=7188

AP
__________________
NAS (N. American Spec) aka NAFTA 2004 OM647 140 2500 Std Roof >271,000 mi. Paint=Arctic Whitewash, DAD
"My opinion and worth everything you'll never pay for it." is expressly implied.
Keeping me on topic will be as successful as herding cats.
Anyone can hold the helm when the sea is calm. Publilius Syrus
"There are only 10 types of people in the world: Those who understand binary, and those who don't." HaWiiLuVeR
Some people have 10 years experience, others just 1 year 10 times.

Last edited by Aqua Puttana; 04-21-2010 at 01:27 AM.
Aqua Puttana is offline   Reply With Quote
The Following 2 Users Say Thank You to Aqua Puttana For This Useful Post:
flynryan115 (07-14-2013), glasseye (07-29-2009)
Old 08-18-2009, 01:44 PM   #5
Aqua Puttana
Poly - Thread Finder
 
Aqua Puttana's Avatar
 
Join Date: Apr 2008
Location: The Falls of Niagara, USA
Posts: 10,751
Thanks: 4,460
Thanked 4,593 Times in 3,051 Posts
Default Re: LHM limp home mode possible causes

I found this description of turbo resonator failure on the Yahoo forum. I think it is well described and worth posting here. Thanks to Stan Fleming for the insight. AP/vic

Classic Turbo Resonator failure - it likely has a weak joint in the plastic body of the resonator - it will "heal itself" when you shut the unit down and it cools a bit, BUT when you put a heavy load on it again (i.e. climbing a hill or accelerating into traffic) the joint will open up again enough to lose turbo pressure - the result is the computer puts the engine in LHM (Limp Home Mode). I suggest you replace the original equipment plastic resonator with the Jim Riordan aluminum replacement.
Turbo Resonator Problem
http://sprinter-source.com/forum/showthread.php?t=796

Stan's post is here:
http://autos.groups.yahoo.com/group/.../message/52503
__________________
NAS (N. American Spec) aka NAFTA 2004 OM647 140 2500 Std Roof >271,000 mi. Paint=Arctic Whitewash, DAD
"My opinion and worth everything you'll never pay for it." is expressly implied.
Keeping me on topic will be as successful as herding cats.
Anyone can hold the helm when the sea is calm. Publilius Syrus
"There are only 10 types of people in the world: Those who understand binary, and those who don't." HaWiiLuVeR
Some people have 10 years experience, others just 1 year 10 times.

Last edited by Aqua Puttana; 04-21-2010 at 01:29 AM.
Aqua Puttana is offline   Reply With Quote
The Following 2 Users Say Thank You to Aqua Puttana For This Useful Post:
flynryan115 (07-14-2013), TimJuhl (08-23-2009)
Old 09-02-2009, 09:36 PM   #6
Aqua Puttana
Poly - Thread Finder
 
Aqua Puttana's Avatar
 
Join Date: Apr 2008
Location: The Falls of Niagara, USA
Posts: 10,751
Thanks: 4,460
Thanked 4,593 Times in 3,051 Posts
Default Re: LHM limp home mode possible causes

Turbo Actuator Frozen Seized P0299 code

This problem was on an OM647 engine, but could apply to others also. After some troubleshooting and testing it was found that it was the turbo vane actuator linkage being frozen that sent the ECU to LHM limp home mode. Thanks to Mwscwan and of course Doktor A.

The link is here:
2005 Low Boost Diagnostics
http://sprinter-source.com/forum/showthread.php?t=7538

AP/vic
__________________
NAS (N. American Spec) aka NAFTA 2004 OM647 140 2500 Std Roof >271,000 mi. Paint=Arctic Whitewash, DAD
"My opinion and worth everything you'll never pay for it." is expressly implied.
Keeping me on topic will be as successful as herding cats.
Anyone can hold the helm when the sea is calm. Publilius Syrus
"There are only 10 types of people in the world: Those who understand binary, and those who don't." HaWiiLuVeR
Some people have 10 years experience, others just 1 year 10 times.

Last edited by Aqua Puttana; 04-21-2010 at 01:30 AM.
Aqua Puttana is offline   Reply With Quote
The Following User Says Thank You to Aqua Puttana For This Useful Post:
flynryan115 (07-14-2013)
Old 09-18-2009, 11:26 AM   #7
gib70
 
Join Date: Sep 2009
Posts: 5
Thanks: 0
Thanked 1 Time in 1 Post
Default Re: LHM limp home mode possible causes

Hi new to forum..
In relation to LHM thrown , I have a 2002 208Cdi sprinter , which I found that the boost pressure valve/sensor wire were broken(1 only). Resoldering the wire definately kept the turbo hoses inflated , so I now have what appears to be pressure.
When the power loss happened , I was doin around 80 km/h , instant power loss and a maximum of 2900-3000 rpm.

When the wire was found I figured it would instantly increase my power back to normal. This was not the case.

Do error codes , fix themselves or do they need to be CLEARED?
Would this instant power drop have caused turbo damage?


Prior to wire correction , the turbo inlet/outlet hosing would not stay hard /inflated.Now it does , but I still only have 3000 rpm maximum.
The van drives OK , but lacks that power boost which is quite noticeable.

Any ideas....

Also ...different problem...What controls the glow plug light?
Mine is staying on. can I pop a relay/fuse to stop glows? Coming into summer here , dont need to glow at the moment.
Thoughts? Sysptoms? cause?

thanks all
Marty
gib70 is offline   Reply With Quote
The Following User Says Thank You to gib70 For This Useful Post:
flynryan115 (07-14-2013)
Old 09-18-2009, 01:16 PM   #8
Aqua Puttana
Poly - Thread Finder
 
Aqua Puttana's Avatar
 
Join Date: Apr 2008
Location: The Falls of Niagara, USA
Posts: 10,751
Thanks: 4,460
Thanked 4,593 Times in 3,051 Posts
Default Re: LHM limp home mode possible causes

Marty,
First a hale and hearty welcome to the forum.

I have copied your question to another section because this LHM thread in Write-ups will be taken way off course if people answer your multiple questions here. I'm as good as anyone (better than most) at getting off topic, but the Write-ups section is a more How-to and informational section than a multiple questions area.

No big problem so no worries. It's just my perception of order.

There is a delete option for your post above if you're OK with where I copied and posted your questions for you. Click on"edit", then "delete", type in the reason for delete. A suggestion is to type "AP was very anal retentive and moved my questions", then click on the final confirmation box. Thanks, AP/vic
__________________
NAS (N. American Spec) aka NAFTA 2004 OM647 140 2500 Std Roof >271,000 mi. Paint=Arctic Whitewash, DAD
"My opinion and worth everything you'll never pay for it." is expressly implied.
Keeping me on topic will be as successful as herding cats.
Anyone can hold the helm when the sea is calm. Publilius Syrus
"There are only 10 types of people in the world: Those who understand binary, and those who don't." HaWiiLuVeR
Some people have 10 years experience, others just 1 year 10 times.

Last edited by Aqua Puttana; 09-19-2009 at 01:43 AM.
Aqua Puttana is offline   Reply With Quote
The Following User Says Thank You to Aqua Puttana For This Useful Post:
flynryan115 (07-14-2013)
Old 09-20-2009, 03:49 PM   #9
Aqua Puttana
Poly - Thread Finder
 
Aqua Puttana's Avatar
 
Join Date: Apr 2008
Location: The Falls of Niagara, USA
Posts: 10,751
Thanks: 4,460
Thanked 4,593 Times in 3,051 Posts
Default Re: LHM limp home mode possible causes

Fuel Pressure Related LHM on post 2003 NAFTA Sprinters

The OM612 NAFTA engines (2001-2003) have a low fuel pressure monitor system and indicator light that shows on the extreme left side of the instrument panel.

LowFuelPress.jpg

That feature is not available on 2004 and newer NAFTA Sprinters (NCV3 included?). For this reason I believe LHM can be set by the ECM if fuel flow is low because the fuel filter is dirty. This would mean that you may get LHM with no MIL (aka CEL) lamp lit. That said, a dirty fuel filter may not be actually causing an LHM operation, but the drive-ability symptoms could be similar. These are my conclusions. Doktor A or Sprintguy would have more details. AP/vic

Single post is here. Original thread is available in upper corner:
Please help / New here / Eliminator problem?
http://sprinter-source.com/forum/sho...51&postcount=2

Does your MIL maintenance indicator light (sometimes called the CEL check engine light) come on at the time of your problems? You really should have the codes scanned.

It sounds like you have a deteriorating condition causing your problems. A total shot in the dark if you are not getting a MIL coming on is to change the fuel filter. It is not very expensive and a dirty filter has been known to affect performance without turning on the MIL. I recently learned that the 2004 models and newer do not have a low fuel pressure monitor system for the 1st stage pump.


Andy Bittenbinder's explanation is here:
Road Trip:St Louis to Jackson, WY
http://sprinter-source.com/forum/sho...93&postcount=4
__________________
NAS (N. American Spec) aka NAFTA 2004 OM647 140 2500 Std Roof >271,000 mi. Paint=Arctic Whitewash, DAD
"My opinion and worth everything you'll never pay for it." is expressly implied.
Keeping me on topic will be as successful as herding cats.
Anyone can hold the helm when the sea is calm. Publilius Syrus
"There are only 10 types of people in the world: Those who understand binary, and those who don't." HaWiiLuVeR
Some people have 10 years experience, others just 1 year 10 times.

Last edited by Aqua Puttana; 04-21-2010 at 01:32 AM.
Aqua Puttana is offline   Reply With Quote
The Following User Says Thank You to Aqua Puttana For This Useful Post:
flynryan115 (07-14-2013)
Old 09-22-2009, 08:15 AM   #10
kitesurfer
 
kitesurfer's Avatar
 
Join Date: Mar 2009
Location: England
Posts: 197
Thanks: 22
Thanked 68 Times in 35 Posts
Default Re: LHM limp home mode possible causes

Ahh this post explains something that was happening on my sprinter a while back that had me very confused.

I run a twin tank veg oil system on my 1996 sprinter. When the engine is cold i run diesel and when the engine has warmed up i run wvo. During the period of setting up my system i had a few teething problems. Mainly with fuel starvation. Some of the plastic connectors i'd put in the modified fuel system collapsed partially, see photos below. This created a blockage that whislt was not a problem at lower revs and loads when i tried to boot it up a hill my engine would mysteriously run out of power. I assumed that if i backed off and ran on diesel again the problem would go away as i thought the veg oil was the problem. Nope the engine remained in this mode, able to rev and tick over but with seemingly no power until i swithced off the engine left it for a couple of mins and then was able to continue on my merry way.
Once i tracked down the collapsed pipes (there were 3 of them ) the problem disappeared. I'm guessing it was the engine swtiching into this LHM mode when not enough fuel was available.

Useful thread this one.





KS
__________________
When i'm not kitesurfing or surfing i'm making surfboards!

KS
kitesurfer is offline   Reply With Quote
The Following 2 Users Say Thank You to kitesurfer For This Useful Post:
Aqua Puttana (09-22-2009), Buckskinner (03-22-2013)
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT +1. The time now is 08:06 AM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright © 2006 - 2012, Sprinter-Source.com