Strange fault codes

[JamesV6CDX]

This question realtes to my 2.5 V6 N reg...

On a drive home from Cardiff this afternoon, I noticed that the Engine Management Light came on for a few seconds, and then went off. Nothing seemed unusual with the car - it was performing fine.

Anyhow, I just thought I'd read the fault codes out of interest, so out came the trusted paperclip,

And with the engine off, I got the codes:

12 (Initiation of diagnosis)

129 (can't find it on topbuzz)

132 (Exhaust Gas Re-circulation (EGR) valve Incorrect signal)

31 (Crankshaft sensor no signal)

With the engine running, code 31 disappeared, so that's not an issue, but 2 questions:

A) What the heck is code 129?
B) What can/should I do about code 132, EGR valve incorrect signal?

Cheers!

James

[STMO123]

If the EM light only came on for a very short time I wouldn't be overly worried. It's a complicated system and prone to spurious signals. The drivers handbook says it may happen now and again.

I understand your curiosity over code 129 though. One of the brainboxes will be along soon I'm sure.

[TheBoy]

Could be the signs of a failing sensor, such as crank, as this tend to cause spurious codes.  Also, just check the battery voltage whilst revving engine is within spec...

[JamesV6CDX]

Better not be the crank sensor. I changed it last month for a genuine VX one, £120 odd later

[djx]

i got 129 too, but i dont know what it is

[Taxi_Driver]

129.....EGR valve feedback voltage low

[Marks DTM Calib]

James

Check your EGR valve connector and wiring loom.....

[v6man54deg Geffd]

As long as the engine management light is not on - the codes are history codes - so not present.
You must have or have had a short on your loom from the EGR valve- check the condition of the loom where it enters the channel on the timing cover - there are a few checks that you can do with a meter - but on one test you need tech 1 in actuator mode - but if the light is not on - then no problem (at the moment)

This question realtes to my 2.5 V6 N reg...

On a drive home from Cardiff this afternoon, I noticed that the Engine Management Light came on for a few seconds, and then went off. Nothing seemed unusual with the car - it was performing fine.

Anyhow, I just thought I'd read the fault codes out of interest, so out came the trusted paperclip,

And with the engine off, I got the codes:

12 (Initiation of diagnosis)

129 (can't find it on topbuzz)

132 (Exhaust Gas Re-circulation (EGR) valve Incorrect signal)

31 (Crankshaft sensor no signal)

With the engine running, code 31 disappeared, so that's not an issue, but 2 questions:

A) What the heck is code 129?
B) What can/should I do about code 132, EGR valve incorrect signal?

Cheers!

James

[Matchless]

EGR incorrect signal and feedback voltage low could be due to the valve sticking. The feedback voltage low/high alarms are  intended to identify broken or shorted wiring but can also come up if the actuator is stuck at one end of its travel when the ECU thinks it should be mid-way.

You could try cleaning it out by removing it and then filling the valve passages with WD or parafin to soften the carbon deposits then work the valve by hand to free it up.
Very stubborn carbon can be removed with paint stripper or oven cleaner but this is a bit of a last resort as it could also attack any plastic bits inside of the valve