Crank shaft sensor repair continued

[sprinternovascotia]

2005 sprinter 2500. 300k

Had a crank no start issue. Intermittent. Finally got it to a shop and got 3 codes:

U0423 - invalid data received from instrument panel cluster control module
P0336 - crankshaft position sensor a circuit range/performance
P0341 - camshaft position sensor a circuit range/performance bank one or single centre

I removed/inspected the camshaft sensor, everything looked good and clean so I put it back and she started. Next day stalled out in traffic and continued to stall so I picked up a crankshaft position sensor and installed it. What a pain. It’s done though.

My questions are:

1. After installing the new sensor the engine light was still on (as I assume it should be until codes are cleared?) next start the engine light was gone. During my no start and stall out issues, dash lights were blinking on and off at random intervals. Sometimes no dash lights for a few seconds...wondering if this is because I was slowly killing the battery as I cranked it, or if it is an indicator that my 3 codes may be related to a ground or other electrical issue ?

2. I had to sand down the new sensor, she wasn’t going in and I’m not surprised considering how hard it was to get the other one (Bosch) out of there. I may have overdone it, it went in pretty nice, a little too nice. Is this ok?

3. If the camshaft sensor appears to be fairly new and in good condition, gasket is good, is there still a chance it is pooched?

Seems odd that all of these codes popped up all of a sudden. Wouldn’t know where to start checking electrical things. I am able to follow instructions but have next to no experience with electrical things. I plan to get the battery tested to make surethats not the issue. Will see if she continues to start and go.

Thanks!

 

[NelsonSprinter]

1. Might be a low battery, or a bad ground connection at engine or battery or firewall
or a frayed worn thru wiring harness

3. Cam sensor may be bad inside, or the connection plug has corrosion

If you see anything green at these connections, it must be cleaned and sanded
It also could be the instrument cluster has a lose connection

 

[220629]

I agree with a thorough check of the battery and related heavy cable system/grounds. That said, there are many other possible causes.

A sensor can appear physically ok, but still be defective.

As long as you didn't sand/abraid through the plastic cover, reducing the sensor diameter a bit won't hurt anything.

Drive cycles can cause the MIL aka CEL dash warning to clear by itself. There is some history of wonky crankshaft sensors causing operating problems without triggering a DTC.

Do you have any idea how old the DTC's are that you mentioned? They may be old codes stored in memory.

vic

 

[autostaretx]

Something to remember is that the cam shaft sensor only "causes problems" when you're *starting*.
During the cranking, the ECM compares the cam sensor with the crank sensor (to locate "cylinder one TDC") and after that
it only uses the *crank* sensor while the engine is running.

So if the engine stops when running, it's a crank sensor problem (as the codes said).

Once you've fixed an issue, it may, indeed, take two or three start/stop cycles to make the light go away.

Your blinking lights may speak of a loose connector on the instrument cluster, or that fuse box one is misbehaving.

--dick

 

[outbound]

Something to remember is that the cam shaft sensor only "causes problems" when you're *starting*.
During the cranking, the ECM compares the cam sensor with the crank sensor (to locate "cylinder one TDC") and after that
it only uses the *crank* sensor while the engine is running.

So if the engine stops when running, it's a crank sensor problem (as the codes said).
............

thanks for this --dick, is the most concise explanation of the functions of these 2 that eye've seen!

 

[220629]

thanks for this --dick, is the most concise explanation of the functions of these 2 that eye've seen!

It is not entirely accurate.

Something to remember is that the cam shaft sensor only "causes problems" when you're *starting*.
During the cranking, the ECM compares the cam sensor with the crank sensor (to locate "cylinder one TDC") and after that
it only uses absolutely requires the *crank* sensor while the engine is running.
...

--dick

The CMP Camshaft Position Sensor Signal is used by the ECM aka ECU for proper engine operation even after the engine is running. If the CMP signal is lost the ECM will impose a max engine RPM limit. CMP signal loss does not cause engine shutdown though. The RPM being limited can help point to a CMP problem.

Loss of the CKP Crankshaft Position Sensor will cause immediate engine shutdown.

vic

 

[outbound]

roger that vic... automotive electrical was never my strong suit...mostly since my chevys never broke
but i did get pretty good at tearing down + reassembling my peugeot and veedub diesels...
both mechanical fuel injected, no ECUs, no goofy sensors (ahhhh... them were the good ole daze

 

[autostaretx]

It is not entirely accurate.

Arm-waves do tend to leave out some details.

The CMP Camshaft Position Sensor Signal is used by the ECM aka ECU for proper engine operation even after the engine is running. If the CMP signal is lost the ECM will impose a max engine RPM limit. CMP signal loss does not cause engine shutdown though. The RPM being limited can help point to a CMP problem.

I merely said (waved?) that it wasn't used, not that it wasn't noticed.
Cam error codes would be logged.

Loss of the CKP Crankshaft Position Sensor will cause immediate engine shutdown.

As waved.

--dick

 

[outbound]

ok you 2, dont be goin all 'danger zone' on us (the last thing the rest of us need is u 2 feudin..

 

[autostaretx]

We're not feuding, we're in full agreement.

--dick

 

[220629]

"Concise explanation" was what prompted my reply for a bit of clarification. I didn't want anyone to get the idea that CMP was completely out of the picture once the engine was started and running.

I believe that the CMP must provide some critical input. Otherwise when the ECM noticed a problem it would simply set a DTC and not impose the LHM style RPM limit. A DTC doesn't necessarily set LHM. The EGR setting a code without any related LHM is one example.

Maybe the CMP input is more critical for the higher ranges of engine RPM?

Anyway...
Back to topic of the CKP.

vic

 

[sprinternovascotia]

Thanks everyone. The small details here are important for my diagnosis.

Because I was having a no start issue - and a stall out issue, I was confused as to whether it was camshaft or crankshaft issue. I am yet to experience any sort of RPM limit which leads me to believe that both the no start and stall out issues are due to a CKP sensor failure.

I had my battery checked and I have 12.78 V, and 974 cca on a 850 cca rated battery. I beleive this is OK. I have driven about 200 km since replacing the sensor and so far so good.

Couple of things to note for anyone diagnosing this issue and replacing the sensor:

- My issue started with a crank but no start issue about once a day after driving over 10 minutes. It got gradually worse and within 3 days graduated to stalling out a few times over the course of a 20 minute drive in the city.

- It was indeed a pain to get out. After reading that they could get seized I feared that mine was stuck for good. If it's tight - don't waste your time with your fingers. Try to get the harness off, it covers almost the entire outside of the sensor, so that you can grab the sensor with some pliers. Twist first, pull, twist etc. Mine came out and was covered in rust as was the slot it sat in.

- If it is Sunday and your handy neighbour is gone and you need your car to go again and do not have access to the E8 torx socket that is required - a 7mm socket will do the trick. BEWARE - If it is too tight or stuck good, it might not do the trick. In my case, I was very careful and it worked fine.

- If you are replacing the sensor from under the vehicle, on the ground, the new sensor will not go in without a bit of a sand. Unless you live somewhere where there is no salt on the roads or in the air and the temp does not fluctuate much, in most cases, I'd say it will need a wee sanding. I'd say go little by little. As mentioned, I overdid it a bit.

over and out.

 

[Patrick of M]

To anyone following this, there is a thread somewhere on sprinter-source explaining how you can cut through the firewall or floor ( ant remember) to get at the CKP sensor. I have done similar things to other vehicles in order to access fuel pumps etc without doing a big disassembly and it is really a time and frustration saver on older rusty vehicles.
p.s. if you use a hole saw the access hatch even looks decent, when it’s all done.

 

[wrabbit]

I detailed how I got a very stuck crankshaft sensor out using a 12" screwdriver, prybar, & channel locks in thread on this issue....
2005 T1N Sprinter Stuck Crankshaft Sensor and linked back to this thread