Need TCM error codes for 2005 3500 dualie

jvf

Member
Hello,
I'll try to keep it brief. Every poor soul's story on this forum could fill a small book. I need a list of all possible error codes that the TCM could throw to prepare for a summit meeting in three weeks with the shop that rebuilt my transmission (truck arrived to them on a hook). As a side note, based on our location, they wouldn't warranty their work unless an aftermarket cooler was installed which I agreed to.

Shortly after the rebuild, I experienced a brief shudder while leaving a stop light. Hmmm. It happened again a couple of trips later so I decided it was time for a return to the shop. Before I did return, a couple of trips later while going around 30-35 MPH I lost all power as the engine revved up like it was just shifted into neutral. After it slowed down some, power returned and I pulled over to go to the market. A few hundred feet later, after leaving the market, this happened again so I got to the side of the road and called the shop. They said bring it over so I restarted and drove the remaining four miles without incident. The pulled codes (posted below) seem to me to indicate an internal problem but I'm fairly ignorant about automatic transmissions (I'm an electrician, auto trannys are a plumbing nightmare). They cleared the codes and went for a test drive without incident. This took a couple of days.

The boss is on vacation but after some calls to him, they started whining about how it was probably the TCM which I should have replaced as well as several other things it might be (although they didn't check any of them). The boss also told them to charge me for this visit considering it to be investigation of a "new" problem. "Not a chance" said I, so the young man in charge wisely gave me the key as I told him I'd attempt to drive it home and leave it there until this was sorted out later (drove the few miles to home also without incident but working out of my wife's peanut SUV sucks and I have to leave jobs early to pick her up).

Unfortunately, I didn't have the presence of mind to see if the dash indicated "N" while I was freewheeling. One reason is that after a few months of driving, the truck lost its ability to manually downshift via the "left clicks" so I don't watch the dash anymore for which gear I'm in. This is a total PITA because I'm always slowly going up a steep grade or someone's driveway and as soon as it levels out a bit, it thinks it can upshift. Not! So, back and forth it goes which can't be good on the transmission. I have been able to mitigate this somewhat by throttle modulation but since the rebuild, this has not been working so well. A couple of years ago a different shop said they thought it was the TCM. But, being an expensive item, I decided to live with it. I questioned if it could be the shifter because it did communicate over the CAN bus but their scanner couldn't tell so I dropped the matter. I had a brief conversation with the Sprinter mechanic at this shop (who just left to start his own Sprinter only shop). He said it was the shifter and not the TCM. He also said the scanner could see the "-" and "+" calls so it could have been checked.

A study of the TCM shows that indeed, it monitors several inputs directly as well as some indirect information over the CAN bus. So, I need to know how many of these signals can throw an error code from the TCM if out of bounds so the shop can't BS me. It's possible some sensors might need to be checked but I don't see at this point how they could cause the TCM to throw 'er into neutral while driving down the street. The Sprinter shop manual's wiring diagrams are mostly s**t so I've ordered an expensive book claiming to have complete and detailed wiring diagrams for every system including connector pin outs, locations, etc. I'm good at checking electrical systems so if there's another avenue to travel down I want to be able to go there first. I'm not trying to pin them to the wall, just trying to help diagnose and fix this.

As a mechanic (but not an automatic transmission mechanic), I can certainly see the shop's reluctance to tear into this thing based on not having it happen to them during a test drive. But, as a vehicle owner, I tend to think that they need to suck it up and consider replacing all components in the transmission that could have thrown these codes unless there is good reason to suspect something else. And, if so, what might that be? I don't think they have a good diagnostician on payroll at the moment. Also, except for the P1 code, these seem like generic codes but they swear their information is correct:

P2500 Improper ratio (slipping)
P2228-001 TCM Transmission ratio error fault present
P1912 Internal controller won't clear (gear selector)
P2333-004 S/C vehicle speed ….. (their copy cut off further written notes)


Thanks,
Jvf

P.S. Shop manual mentions a PCM (module?) but doesn't give any description. What's that? Also, there is mention of a PCI bus. Is this separate from the CAN bus or is it another name for the low speed CAN
 

lindenengineering

Well-known member
From your narrative the transmission appears to be defective internally.
The unit needs to be base lined first and not immediately blame the electronic controls /management as the culprit in this case
The first code you have posted is the indicator.

Now I have got tangled up in a dispute like this where a DIY'r installed a rebuild transmission and it exhibited the same faults as your description. It was then like a badminton match with the blame game shuttle cock to 'n fro "To you Sir" --"No to you Sire" and so on.

To resolve the issue once and for all as an accidental arbiter, I simply put a good known used transmission into the the van, swapped from a perfectly good donor van and it worked fine. Then of course the finger pointing had to stop, & it was reluctantly concluded that the rebuilt transmission was no so well rebuilt, or reconditioned.
And so!
Here endeth the transmission fault fable that some in the trade I have been in for more than 60 years!:laughing:

Hope that helps.
Dennis
 

jvf

Member
Thanks Guys,
This is great info. I'm studying the scanner forum to choose between the Autel or iCarSoft. Should I start a new thread about the shift lever? I'm hoping to get to it without breaking the top of the instrument panel as I pry it up. Hopefully there is reference to it in the body section. I can't find a detailed description of how it sends the shift positions (contacts, hall effect switches?). It's Mercedes expensive also so I'd be interested if it could be disassembled enough to try to clean anything and try it again.

jvf
 

lindenengineering

Well-known member
If you want wiring diagram and full descriptive info on the transmission, repair functions and diag your best bet is to buy a transmission repair manual from TransStar , at about $40 its money well spent.
The up shift control is merely interrupted the up shift signal from the TCM which is routed through the shift lever control.
At an ordinary mechanic entry level a Snap On scan tool delivers the goods in that sphere of operation including the diag' path in the Shopkey feature.
All the best
Dennis
 

jvf

Member
Hi Dennis,

I'm going to try to get the TransStar manual. I have a fair amount of SnapOn tools but Its been many years since I've been a full time auto mechanic so it's unlikely I'd ever subscribe to ShopKey.

During one extended visit in the previous shop, they were floundering around and the service manager kept assuring me that their "best tech" was on it. "I don't want a technician working on it" I bellowed, "I want a MECHANIC". A couple days later he said "You know, John, you're right. You're like my father. He knew how to figure out and fix things. These kids today only know how to read codes and replace parts."

Score one for the old guys.
 

jvf

Member
Hello everyone,

I'm digging through the manual/links/ literature and keep finding references to the test procedure but I can't find the procedure:

"Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/ TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)"

Any clues as to where this procedure is located?

Thanks,
jvf
 

autostaretx

Erratic Member
Hello everyone,

I'm digging through the manual/links/ literature and keep finding references to the test procedure but I can't find the procedure:

"Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/ TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)"

Any clues as to where this procedure is located?
Chapter 21 in the main service manual: http://www.diysprinter.co.uk/reference/2006-VA-SM.pdf perhaps?

(which has only a couple of sub-sections called "Standard Procedure", so which *page* it is depends upon the test needed)(the two are 42 and 132)

--dick
 
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jvf

Member
Thanks dick,
There are several "Standard Procedures" throughout the manual but nothing refers to the "NAG1 Transmission Verification Test". Bummer!

Merry Christmas to all,
jvf
 

autostaretx

Erratic Member
Ahh... found it.

It's in the 2006 Transmission manual, page 127 (by the on-page number) or acrobat's page 131 (of 144 total).

---quote---
1. Reconnect any disconnected components.
2. Connect the DRBIIIt to the Data Link Connector.
3. With the DRBIIIt, erase ABS DTCs.
4. With the DRBIIIt, erase ECM DTCs.
5. With the DRBIIIt, erase Transmission DTCs.
6. With the DRBIIIt, display Transmission Temperature. Start and run the engine until the Transmission Temperature is HOT, above 43° C (110° F).
7. Check the Transmission fluid and adjust if necessary. Refer to the Service Information for the proper Fluid Fill procedure.
8. NOTE: If internal repairs were performed and the shift quality is still poor, it may be necessary to check the internal repair. Also check for any TSBs and/or Controller Flash updates that may apply.
9. ROAD TEST PROCEDURE
10. Road test the vehicle. Make fifteen to twenty 1-2, 2-3, 3-4 and 4-5 upshifts.
11. Perform these shifts from a standing start to 72 km/h (45 MPH) with a constant throttle opening of 20 to 25 degrees.
12. With speeds below 40 km/h (25 MPH), make five to eight wide open throttle kickdowns to 1st gear. Allow at least 5 seconds each in 2nd and 3rd gear between each kickdown.
13. With the DRBIIIt, read Transmission DTCs.

Were there any Diagnostic Trouble Codes set?

Yes ! Repair is not complete, refer to appropriate symptom.
No ! Repair is complete.
-----end quote----

--dick
 

jvf

Member
Excellent Sir,

Thank you very much. As I suspected, the procedure involves connecting to the Mercedes Benz OBD III system which I doubt they have. But, I'm going to ask which scanner they use. The goal is to reach an agreement with the shop on how to proceed. Per the diagnosis manual, the "Improper Ratio" error calls for mechanical inspection first and if none is found, replace the TCM. Having just rebuilt the transmission you can imagine what they're going to say. And, even if I convince them to take a look, the problem is still intermittent so they might not find anything. From what I gather, with good enough diag. equipment they should be able to operate the solenoids and monitor if anything sticks but I won't hold my breath waiting for that.

Meantime, the presents were opened early and no football was in evidence so I went out and pulled the shift assembly. Unplugging the electrical connector was a real b*tch. I feel like the dog that finally caught the bus. Now what?

jvf
 

jvf

Member
Well,

What I do with the shifter before I rip into it is reconnect it and test with the (just ordered) iCarSoft scanner as it can read the jog positions.


jvf
 

autostaretx

Erratic Member
jvf wrote: "(electrician, not a tranny mechanic)..."

Well, at least the shift lever assembly (SLA) is 99% electronic ... the gear selection lever is moving a potentiometer, and the side-to-side motion pushes on switches .

There has been (at least) one photo-essay on the SLA disassembly ... (i'll try to find it ... in a few hours done)

When it was posted, i screen-grabbed the text and a few of the follow-on comments:
===quotes start====
midwestdrifter wrote:
The switch consists of a floating spring contact set which is attached to a plastic ring around the metal rod the knob is mounted to. Disassembly requires the security torx bits (little nub in the center).

There are two circuit boards inside. One at the top front where the harness plugs in, and another below the indicators alongside the shifters travel slot. They are connected with a 5/6 wire 2" long harness with two plugs. It is very difficult to remove without damaging the socket, so take care.

In order to get to the switch you must seperate the main housing. Then remove the top (backlit) cover from the upper circuit board (the D-N-R labels are on it). I am not 100% sure, but you may have to separate the upper/lower halves off the casing to drop the upper circuit assembly out. It has its own separate plastic housing, and slots in from the bottom of the upper casing half. There are a couple of clip/tabs that you can access from below, and use a flat blade screwdriver to unclip.
-------------
LS1K5 wrote:
By a combination of luck and skill I managed to get my manual shift mode working again without breaking anything in the shifter. Two of the contacts in the shifter selector were damaged but I fix them well enough for now, here are some photos that may help anyone doing this in the future.
--------------
midwestdrifter wrote:
the fabric scroll that covers the slot can easily be installed backwards. Yours is correct though. Take care to align the top and bottom of the case so that the shifter is centered in drive.
===quotes end====

But :doh: i didn't grab the address of the thread....

Found it: https://sprinter-source.com/forum/showthread.php?t=65581

--dick
 
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jvf

Member
Thanks dick,
This gives me some hope that I could repair something if necessary. I have the security torx bits so I'll dig in later this week. Meantime I'm going to start another thread asking about the "improper ratio" error message. I don't have the transmission book suggested earlier and I need to know what sensors/information the TCM uses to determine this problem. If they are all internal to the transmission then I can argue to the shop that regardless of suspect inputs, these are the only ones that are relevant in this case.

jvf
 

autostaretx

Erratic Member
The transmission uses a solenoid plate to control the shifting.
Most of the (non-lack-of-fluid) "it's in the transmission" problems are due to failures on that plate.
The plate is available as a replacement part.

There have been photo essays in the forum showing the removal/cleaning/installation of that plate.

Here (once again) are the links to the Service Manual and the Transmission manual.

--dick
 

jvf

Member
Hello dick,

I'm sure they replaced the solenoid assembly. The owner was mumbling about not being able to get it short term from a supplier he trusted so maybe he got what he could and it's not up to par.

I do have both documents. I've had the service manual for quite some time. Heavy reading, eh? Months, if not years, of study including hands on training would be necessary before I could hold my own in a shop dispute. So, I can only concentrate on a narrow frame of reference and hope it gets me somewhere in terms of the ultimate solution.

Among things I've learned are that the TCM will throw the transmission into neutral if it thinks the world is about to end and the N2-N3 sensors are internal hall effect switches on the electromechanical plate (forget its proper name for now). There is also mention of comparing these readings with engine speed but for the life of me I can't find any mention of an actual engine speed sensor in the manual.

" Signals from the input speed sensors (6, 8) (Fig.166) are recorded in the transmission control module (TCM) together with the wheel and engine speeds and other information and are processed into an input signal for electronic control."

The manual gives a fairly detailed description of transmission events but leaves out a description of the state of things when neutral is engaged. Probably because it's obvious but I've only built and serviced a few simple hydraulic systems and am not yet fluent in hydraulic diagrams (need to have all the symbols handy). I'm trying to follow the fluid path to see what is happening in neutral. I thinks all the solenoids are off and this engages (disengages?) K3.

This would be a lot more fun if I were trying to help a friend instead of myself.
 

autostaretx

Erratic Member
The crankshaft position sensor is also the "engine speed" sensor.

It watches the starter ring gear teeth go by, and is used to determine instantaneous speed variations based upon crankshaft angle.
That info is used to determine misfirings and (if just being cranked by the starter) a quick compression test (as the crank speeds up and slows down).
---------------

As for "Neutral", chapt 21 page 36 (in the 2006 service manual) seems to be about "it" ... the text describes the valve states just prior to engaging 1st.

--dick
 
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jvf

Member
Crankshaft position sensor—that's the phrase I was trying to recall. Thanks! I vaguely remember when they were first introduced. What strikes me as odd is that the transmission diagnostic procedure for "improper ratio" doesn't mention checking this or the wheel sensors. It just says to look at the transmission innards and if nothing looks amiss, change the TCM. If the TCM is calculating speeds by comparing the various sensors and sees (or thinks it sees-which will be my shop's argument and who's to say?) a major discrepancy how can this be sorted out? Unless the sensor returned an out of bounds value and generated an error code there would be no way to tell. This is why I'm trying to at least check the wiring to each sensor. It's also another reason I'm going to start a new thread and try to get some responses from those who have seen and repaired this error and what the solution might have been.

I've built a fair amount of machines and test equipment using microprocessors and hall effect switches. In my experience, when the microprocessor goes, it never returns-it either works or doesn't. Hall effect switches can fall prey to increased magnet distance and then things can get erratic but again, once it starts happening it happens a lot, not once in a while.
 

220629

Well-known member
From a closed thread.

Need help troubleshooting Improper Ratio codes

Hello,

I need some help in determining a course of action to remediate "improper ratio" error codes in a newly rebuilt transmission. If anyone here has experience in troubleshooting these codes I'd be very interested to hear what happened.

I recently needed to have my 2005 Sprinter 3500 transmission rebuilt and received a 24mo/24,000 mile warranty after I agreed to let the shop install an additional cooler. Shortly thereafter, it shuddered briefly taking off at a stop light and a week later it happened again. I don't drive the truck often so I resolved to stop by the shop some day soon for a discussion. Before I did, something else happened. While driving around 30-35 mph, the transmission went into neutral and the engine revved up. I of course let up on the gas pedal and as the truck slowed down it found a gear again so I continued a for block or so to pull into a small shopping center and purchased a couple of items. Somewhat apprehensively, I decided to head for home. I proceeded without incident for about ½ mile at the previous speed and the above scenario repeated itself again. This time, I pulled over, called the shop (about 4 miles further up the road) and they said to bring it over. So, I gritted my teeth, started 'er up and the thing drove right to the shop without complaint traveling around 45 mph and going up several rolling hills.

They cleared the codes (description and comments by them):
P2500-Improper ratio slipping
P2228-001 TCM-DTC transmission ratio error fault present
Gear selector:
P1912- Internal controller won't clear
P2333-004 S/C vehicle speed plausibil….(rest of text cut of on my copy),

checked the oil level and electrical connection and test drove it without incident. They muttered about possible electrical problems or a failing TCM module, declared this to be a new problem external to the transmission and not covered under warranty, and so were not at all interested in tearing into the transmission (can't say I blame them for that). The owner was/is on vacation for a couple of weeks and there was no one to really discuss the situation with. So, I drove it home (another 4 or 5 miles) without incident and there it sits while I await the owner's return so we can sit down and talk.

Gear selector: I have had this vehicle for several years but it's my retirement truck so I've not piled up a lot of extra mileage. A couple of months into it, I lost the ability to manually downshift. A total PITA going up slopes or driveways because as soon as it would level out a bit, the tranny thought it could upshift. Shop at the time said it was the TCM. I disagreed because I knew the SLA was connected to the CAN bus and thought it might be defective. But, that shop didn't know how to test it just wanting me to spend several hundred dollars on a TCM module. I declines and learned to mitigate the upshifting to an extent by modulating the throttle. But, I can't take it anymore. I had a conversation with this shop's former Sprinter mechanic and he said it was likely the SLA and the +/- jogs could be observed on a scanner. I have since purchased the iCArSoft MB II which, according to this forum, can indeed read these jogs. As I wait for this meeting, I have removed the SLA. The replacement would be a new one so I don't have to supply a good core. Therefore, I am going to dissemble it in an attempt to effect repairs and save spending another $500 on a Mercedes part. In short, I don't think the SLA has decided to start causing the TCM to throw the transmission into neutral but I'm sure this shop will point to the SLA as a possible cause.

So, in preparation for this meeting, I am trying to learn as much as I can about possible causes for my truck's behavior. I have a copy of the manual and, with the help of others here, I have gathered quite a bit of useful information concerning transmission troubleshooting. I have also ordered a comprehensive wiring diagram manual.

The shop's Sprinter mechanic left recently to strike out on his own. And, although this is "just" a Mercedes transmission I am suspicious that the shop is woefully short on diagnostic power at the moment which is why I'm asking for advice. As I mentioned in my other post it would take months, if not years, of study and hands on training for me to carry on an intelligent conversation with them so I'm trying to learn what I can ASAP In case the BS starts flying. If this is a "different problem" I am not confident that they will have an appropriate list of things to test other than to just start replacing (expensive) parts and hoping for the best so I am trying to prepare a troubleshooting diagram that concentrates on how and why the TCM would generate this error and throw the transmission into neutral.

Unfortunately, the diagnostic information provided in one of the forum's great links, is rather cryptic. If oil level is OK, it says check electrical connections (and version of TCM software but I think that's a dead end) and if things look good, inspect the transmission for mechanical problems paying attention to the valve body and stuck solenoids and if nothing is found, replace the TCM.

As the vehicle owner, I suppose I could try and force them to have a look but, since everything is supposedly new/rebuilt I'd actually be surprised if they found anything. What then? Force them to rebuild it again? Let them charge me for a replacement TCM and then incur a towing charge later which could likely exceed the price of the TCM? I'm in a real quandary here and just want to find a solution, not argue with them that it's internal and they need to do something.

I was trying to determine the state of the transmission when in neutral but I can't tell from the hydraulic diagrams. Are all solenoids off and this somehow sends pressure to the K3 clutch?

In any case, would there be additional error codes pointing to one of the solenoids or sensors?

Sorry for the verbose post but was trying to give an accurate description of events.

jvf
 

Eric Experience

Well-known member
JVF.
This is very similar to Lionen's story with his diff. If the re builder used a gear set from a used transmission there is a good chance that it was not the correct ratio, if it came from a car it will not work and will chuck a slipping code. Eric.
 

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