Error ECM-952F accelerator pedal position sensor

[VolvoRob38]

Hi all,

Been having an issue with my accelerator pedal position sensor on c30 SE 1.6d 2009, (Reduced engine performance message) car idling at 1500rpm and shoots along the road when I take my foot off the accelerator. Kept having to take it out of gear and freewheel.

I plugged my dice in and Vida displayed the ECM 952F error, relating to the accelerator pedal position sensor. In the repair section it suggests to firstly test the voltage in the pedal sensor cable connector to check for 12v with key in position ll. I tried positions 0 and l and ll and engine running, all accept position 0 returned a reading on my multimeter 5v - 8v (decreasing to around 6v). Based on this I ruled out the pedal itself as the problem seems to be further up the circuit.

The next thing it says to try if the voltage is incorrect is to check ground, check between sensor cable plug and relevant fuse, and for any loose connections along the cables, as well as oxidisation. I don't know how to do any of that, partly because my multimeter isn't long enough to reach from the sensor plug at the accelerator pedal to the fuse box under the bonnet, and neither are my arms. But also I cannot see where the accelerator pedal sensor cable goes to in the engine to check for loose connections, which also doesn't help me check for oxidisation (I assume that means corrosion from outside air?)

I have some other error codes relating to SRS and ICM, so checked the relevant fuses in the CEM under the glove box. These fuses were somewhat difficult to get out and felt like they were welded in there. I removed them, checked them and all was OK.

Now when I started the engine, no reduced engine performance message! I rev the engine to 3-4k revs and still no errors, car idling normally. I took the car for a drive and put my foot down trying to recreate the issue, but nothing, car is back to normal after about 2 weeks.
This leads me to suspect the issue might be in the CEM somewhere, but after wiggling the wires and playing with the cem unit while the engine was running I have not found anything or been unable to cause the problem again.

Based on this knowledge does anyone have experience with a similar issue and/or have any idea exactly what/where an issue might be in the CEM that would affect the accelerator pedal?
Could it just be a dirty CEM that needs some contact spray in the connectors?

Thanks

[mypaulra]

Hi have you checked out this thread

https://www.volvoforums.org.uk/showthread.php?t=295210

Similar issue but on a S40.

[VolvoRob38]

Originally Posted by mypaulra

Hi have you checked out this thread

https://www.volvoforums.org.uk/showthread.php?t=295210

Similar issue but on a S40.

Hi, thanks for this. I will use it to try and locate/test the specific part in the CEM.

[VolvoRob38]

What is an OEM diagram, and are/Should they be available in Vida?

Thanks

[kostecki7800]

Hello. Ive got the same problem. Have you found the solution already?

[VolvoRob38]

Originally Posted by kostecki7800

Hello. Ive got the same problem. Have you found the solution already?

Hi, I did but I cant remember exactly what it was now. I think it was something to do with the (CEM is it?) board under the dash in the passengers footwell. I disconnected all the wires and cleaned the board and connectors with contact cleaner. Ive not have that specific issue come back... yet!

I believe it was something to do with one of the wires in one of the plug either corroded or just not connecting properly. Someone shared a diagram on here which showed the exact pin that needed replacing, but cant find it now. See if you can find it in my posts on my profile. I never had to go to that extent anyway after using the contact cleaner.

I am getting the Reduced Engine Performance message again now, but no issue with revs. plugging the DICE in it looked like it could be Glow Relay control, which I think has something to do with spark plugs.

[andy_d]

Originally Posted by VolvoRob38

Hi, I did but I cant remember exactly what it was now. I think it was something to do with the (CEM is it?) board under the dash in the passengers footwell. I disconnected all the wires and cleaned the board and connectors with contact cleaner. Ive not have that specific issue come back... yet!

I believe it was something to do with one of the wires in one of the plug either corroded or just not connecting properly. Someone shared a diagram on here which showed the exact pin that needed replacing, but cant find it now. See if you can find it in my posts on my profile. I never had to go to that extent anyway after using the contact cleaner.

I am getting the Reduced Engine Performance message again now, but no issue with revs. plugging the DICE in it looked like it could be Glow Relay control, which I think has something to do with spark plugs.

if you follow the vida test and repair steps for the "glow relay control" the issue should be fixed by the time you get to the end

your right, the glow relay control IS part of the circuit for the Glow plugs (diesels have those spark plugs for petrol engines)

[VolvoRob38]

Originally Posted by andy_d

if you follow the vida test and repair steps for the "glow relay control" the issue should be fixed by the time you get to the end

your right, the glow relay control IS part of the circuit for the Glow plugs (diesels have those spark plugs for petrol engines)

Thanks Andy,

I'll give that a try tomorrow. Ye I just heard diesels dont have spark plugs haha... this is my first diesel

[VolvoRob38]

Originally Posted by andy_d

if you follow the vida test and repair steps for the "glow relay control" the issue should be fixed by the time you get to the end

your right, the glow relay control IS part of the circuit for the Glow plugs (diesels have those spark plugs for petrol engines)

Hi Andy,

I went through the steps again today and looks like I need to locate the relay in the ECM and try cleaning with some contact cleaner first. Is this a relatively easy job once the wheels off?
What about changing the glow plugs first??

Ive got a bit of an issue with the nearside front wheel because I stripped the nuts a bit when changing my alloys, trying to tighten them efficiently by standing on the wheel brace. Im gona have a nightmare/fun getting those off.

[andy_d]

Originally Posted by VolvoRob38

Hi Andy,

I went through the steps again today and looks like I need to locate the relay in the ECM and try cleaning with some contact cleaner first. Is this a relatively easy job once the wheels off?
What about changing the glow plugs first??

Ive got a bit of an issue with the nearside front wheel because I stripped the nuts a bit when changing my alloys, trying to tighten them efficiently by standing on the wheel brace. Im gona have a nightmare/fun getting those off.

total PASS on what/where with anything diesel

on the Wheels front
oh dear,, oppsie

stripped wheel studs will be a Bit of a buuuuger to sort out and sadly Need to be as a wheel going "bounce" down the road while the car goes "Grind" and you watch the wheel + sparks,,,

https://www.halfords.com/tools/garag...ve-226636.html in 24inch + socket to fit wheel nuts - removed ,, stow in boot for "oh bugger" moments out n about along with
https://www.halfords.com/tools/hand-...00-488703.html

Or

https://www.halfords.com/tools/hand-...00-488729.html

85nM for the wheel nuts When you have sorted them
trust me £100 for a torque wrench V the cost of "sparks and wheel disappearing" is Cheap and worth the £100

if you mean the "CEM" then thats in the passenger foot well, DO disconnect the battery before playing with it ,, and Dont reach Over or Between the steering wheel to turn the key for the 1st time After reconnecting the battery,,,