V50 General : Related problems? Accelerator sensor and Anti-skid warning

[rkthornley]

Recently my '05 plate V50 2.0D suffered power loss, delayed throttle response and appeared to limit its revs to about 2900RPM. I also had one instance where I had no throttle at all.

Learning from previous dead end fault finding sessions I took it straight in for a fault read. I'm glad I did as it flagged up a "accelerator sensor signal fault" (I had previously suspected boost solenoid/MAF!). Reading the values from the sensor indicated it was working ok (readings up to 99.9%) but the fault kept coming back on start up.

This all makes sense to me; the car is drive-able (the accelerator still basically works) but sluggish (the car is limiting its power as it knows there's a problem), the instance of no throttle was presumably when the sensor failed totally but temporarily.

But... before I replace an expensive accelerator assembly....

I have the dreaded Anti-Skid warning light and had previously diagnosed this as the "common volvo ABS fault". I was weighing up what to do about it (traction control is disabled but ABS still works) when the above fault came up too... The actual fault is "brake pressure sensor" and I know there is a sensor on the brake pedal, so could these faults actually be part of a module common to the pedal sensors? Or the wiring between the two? (I have noticed that the previous owner had a hands free kit that was removed).

Note: Fault reads all done by a generic fault reader at my local garage, I saw on other threads that sometimes they don't give you the full fault code.

Comments/criticism(!) gratefully received, I'm flying a bit blind and don't have too much money to throw around! I had a nightmare experience with an Audi A4 that was plagued with faults so I traded it in for a safe reliable Volvo... (

[rkthornley]

Hmmm.... disappointed no-one has any comments.

Further to yesterday; I read some articles about issues with ETMs... these seem to be on older models, could this be an issue with my V50? I have previously noticed a bit of a blip/flat spot around 2100rpm, could this be related to an "accelerator signal fault" (of course, the answer is yes but could it point to something else too/instead!?)

I convinced myself yesterday that it was a wiring fault. I read an article about someone who noticed a common fault on V50 T5 pedal wiring (rubbing on the clutch and wearing through) so before I drove home last night I had a poke around and moved some cables.... bingo, full power again! (Plus auto-climate seemed to want to default to off/fan only - could this be related to wiring too?)

But not for long, back to limp mode this morning.

[ajlongfield]

Sounds like I have a similar problem. I also had the dreaded anti skid service required not long after buying my Volvo V50 1.6d (2009). I am in france for 6 months and it did it on the way down so have had trouble getting it booked in to Volvo. Anyways after some fault finding I have had the EGR valve replaced and also filled the dpf additive (as this was out). Now the anti skid message has gone accept for if I’m trying to get up steep hills then it kicks in but goes when I restart the car. Since the first time the anti skid message came up I have been in slow/limp mode.

Managed to get the Volvo garage to hook it up to there diagnostics and actually on the way down the message ‘reduced engine performance’ came up (like i didn’t know!) anyway the guy said an error on the accelerator pedal was coming up. I’m thinking it could possibly be a wiring issue as you have alluded to. I am going to take the plastic cover and whatever else I can get off under the stirring wheel and have a look/fiddle see if I can see any loose wires etc.

I have it booked in with Volvo 21st October so will wait and see. The guy seems decent and actually but it on diagnostics a couple of times and didn’t charge. Will keep you updated!

[jaffattila]

Hi
I have a V50 1.6D DRIVe 2011 model which recently came up with the known message "Reduced engine power engine service required". I have a VIDA 2014 which I have purchased to refill / reset the DPF additive tank and make a forced DPF cleaning few weeks ago.
Now I read the codes and find 3 codes stored:
CEM-3F93 Accelerator pedal sensor Signal too low
ECM-952F Accelerator pedal sensor - Faulty signal
ECM-9530 Accelerator pedal sensor - Signal missing
I have tested the accelerator pedal signal using VIDA and I have spotted some glitch in signal response to pedal movement. I mean pressing the pedal slowly but continuously in and than releasing it the curve which VIDA draws stops stays and than jumps up or down depending whether the pedal was pressed in or released.

There are lots of writing and a very useful video about unreliable connections to CEM and in lots of cases people had success disconnecting connectors cleaning them and the failures disappeared.
I have tried the same as well but after that VIDA testing shows the same behaviour. I have tested both CEM and ECM simultaneously as there are two signal actually (redundancy). Now both signal behaves in the same way and produces occasionally the same glitch described above.

Here are some VIDA 2014 screen shots about my measurements:
https://photos.app.goo.gl/yR6tsUwKoKjH99BCA

Now my question is that, is it possible that the sensor is faulty? I read that happens very rarely.

Thank for your time and hoping for some help
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