Engine Management Fault ?

[Mike M.]

2006 petrol C8, driving at 30mph when the engine management fault light came on. No indication as to what the fault might be, but the car immediately slowed to approx 5mph and continued at that speed "kangarooing" as if I was a brand new learner driver. Got it to a car park, turned the engine off, waited a few minutes, turned it back on and the fault light lit up and the revs would not go above 1500rpm. Left it for 30 minutes or so, started it again and all was normal. Drove it home (8 miles or so) with no problems whatsoever. Used the car the following day also without problem. My worry is - now that the "apparent" fault has not recurred yet, what a problem I will have if it does happen again on a busy carriageway. Anyone have any clues what the fault might actually be?...or has anyone experienced anything similar?...any information would be much appreciated !!!!!!  Mike M.

[paul.h]

Since the light came on there will be a stored fault code which you need to read to see what is wrong. It could be a crank shaft or cam shaft sensor or something else but to start replacing parts could cost  a lot before you find any faulty ones without reading the fault code.

[Mike M.]

Hi, Thanks for that, I did access the fault record using the menu system but all it said was "Engine management system fault" I don't know any other way of finding the fault code. Regards, Mike M.

[paul.h]

You need to use a fault code reader which plugs in to the EOBD 16 pin socket. I do not know where it is on the C8 but often on Citroens it is on the cabin fuse box. It is cheaper to buy your own reader than pay a garage to do a diagnostic check. This one from Gendan also gives some live data as well as the engine fault codes https://www.gendan.co.uk/product_FXNT200.html

[Simple]

The OBDII connector is below the steering column in the C8. If this Citroen C8 is for keeps, I agree with Paul that it would be wise to buy an analyzer.

 

However, I doubt that you will get the real reason of the fault in this case. Sometimes you get an intermittent fault, which will show under certain conditions such as circuit dry joint, low/high temperature, low/high power and/or rain.. etc. But it looks like yours was caused be either a loose/shaky connector that is not properly plugged or chaffed wire or very law charged battery.

 

In the mean time, I would advise that you unplug and re-plug all connectors to all sensors that you have access to, especially the MAF (Mass Air Flow sensor).

[Mike M.]

Thanks to both for your help. I've used the car again today and all is still well. I've arranged to have a scan done at my local garage for £18 (Citroen dealer wanted £78 to do it) but I don't expect it to show much, I've had a look at the Gendan fault reader mentioned by Paul and agree buying one would be a good idea, and probably will do so, but in this case I also tend to agree with Simple that there's a good chance that it could also be an intermittent fault with a relatively simple solution. The reason I say that is because the road I was driving along at the time the event occurred did have some rather vicious speed humps so the loose connector theory could be the first avenue of exploration. I need to do a little more research into fault readers though - I presume that if a fault occurs then clears as this one has done then a fault reader wouldn't be able to detect it - or am I wrong?

[paul.h]

If the engine management light comes on the fault code is stored until it is deleted using a reader, even if the light goes off and the fault clears. Please let us know what the local garage finds and make sure you note down the code(s) before it is deleted.

[Mike M.]

Hi again Paul, Local garage results are P0571, P1160, and P1161............P0571 is listed as Brake switch "A" circuit, but the other two seem to be open to debate about what they mean exactly. I've searched several sites and the clearest description I can come up with is P1160 Intake manifold, and P1161 Throttle motor position. 

Re. your advice about a scanner, the Foxwell NT200 is in stock at £38.95, but they also have a Foxwell NT301 at the discounted price of £55.00. Would it be worth me paying the extra £16 or so for the extra features?

[paul.h]

There does not seem to be much difference in the 2 code readers, the dearer one gives graphs ot the values which may help you on live data seeing how a value changes but you can get that by watching the value itself. However, for £16 extra it is probably worth it.

 

P0571 Cruise Control/Brake Switch A Circuit Malfunction - possibly the brake pedal switch or its connector/wiring are faulty.

 

A search on P1160/1161 suggest you should check the ecu connectors for water ingress/corrosion before doing anything else. You could also check the throttle body is clean internally. Disconnect the battery first before checking the ecu but do not do it too quickly to avoid possible electrical problems. Have a check in your handbook but I have used the following procedure on our Citroens:

 

11. Odd electrical problems caused by wrong battery disconnection procedure.

If you need to disconnect the battery and not do a BSI reset procedure, I have found the following has not given me any problems on a 2004 and 2007 C5 and a 2003 C3:

- remove the ignition key from the car

- open the bonnet

- wait a few minutes for the BSI to shut down

- disconnect the battery negative terminal

 

When reconnecting

- ignition key out of the car

- reconnect the battery

- wait a few minutes

- insert the key in the ignition and wait a minute

- turn the key to the first position and wait a minute

- turn the key so the dash lights come on and wait a minute

- start the engine

- take the windows down and up to reset the anti pinch

- reset the clock (and radio on the C3).

 

In the handbook for the 2015 C4 it says to wait at least 2 minutes after switching off the ignition before disconnecting the battery and when reconnecting, to wait at least a minute after switching on the ignition before starting the engine.

[Mike M.]

Thanks again Paul. No cruise control on this car so I'll check over the brake pedal switch/wiring as you suggest. (That fault was generated a good few months ago and has never recurred since.) As for the other two, as far as I can find out they usually seem to happen together, but the exact cause seems to be unclear. I'll do the checks you suggest however and see what happens. First problem is relatively minor - don't know where my radio code is recorded!! Also, I'll get my own reader as you advise. I'll keep this thread updated.

[paul.h]

If you disconnect the battery you do not need a code for the radio if it is the original Citroen one.

[coastline taxis]

The throttle body needs cleaning. use brake or clutch cleaner .  never cleaned one on a c8 so I cant give you a run thru but as a rule its a very easy job

[Mike M.]

Update as promised. So far I've only gone as far as unplugging, cleaning and replugging any connection I can find that looks like a sensor connection. The reason I've not investigated further is because the car has now, since the fault occurred, been driven over 700 miles at both town and motorway speeds without any further problems. I purchased a fault code reader (Thanks Paul) and a check yesterday showed no faults recorded. In case it does happen again I'll keep a record of the advice in this thread for future use. Just a final note - I've had this car for about 7 years and found it a generally reliable and versatile motor (sliding doors, removable seats, high headroom etc.) but it does seem to have a few random electrical quirks from time to time. The abs failure light has come on twice, but has gone out after a few minutes or so, the electric windows sometimes refuse to go from open to fully closed in one fluid motion now and again and need "stabs" at the button to get them shut, and now this latest engine management fault has shown up. All part of the joys of motoring I guess!!!  Mike M. 

[Simple]

These quirks are BSI issues. I also have them from time to time. It is possible that errors/corruption has occurred in the program due to interference or low power. reset your BSI, there is a procedure (in one of the posts) for the C8, since the battery is near the driver's seat. Ensure you have fully charged battery at all times.

 

For the ABS, follow the cable and you will find a connector on the inner side of the wheel arch (for each wheel), ensure they are clean and properly connected. But it could be that the wheel spun or locked over gravel or something!

Edited July 24, 2016 by Simple