1.4 automatic p0609 p0108 fault codes

Hi everyone
My other half's 2004 C3 1.4 automatic has just started to play up in the last few weeks and has now become so bad we've bought her a cheap run around while I try and get to the bottom of the fault(s).
She's been brought home by the AA twice in the last month
The car starts first time on the button, all electrics function properly but the car will only drive at 8mph maximum (I assume its stuck in limp mode). Tick over is smooth with no sign of missfire.
Revving via the throttle pedal only revs the engine to 2000rpm max, Manually reving the car slowly off the throttle body allows the revs to climb to 5000rpm +, Attempting to manually rev it quickly causes it to automatically back off the fueling.

The engine management light is on.

Current error codes that wont clear are -
P0108 - manifold absolute pressure or barometric pressure circuit high input.
p0609 - control module vehicle speed sensor output b malfunction.

In the last few weeks in an effort to resolve the problems (and under the advice of the chaps from the AA) I have changed the following items -
MAP SENSOR
Coil pack
Spark plugs
throttle body
(All parts fitted were brand new)

And in addition to the above I have also sealed off the washer jets to prevent the "drip" problem
The chap from the AA recommended that I check the ecu for any signs of water ingress but the Sagem unit appeared bone dry and the circuitry was completely encapsulated in silicone.

One thing I did notice is that my mac tools diagnostic unit has live a live data function and when revving the car the manifold pressure is static, no change whatsoever. Even removing the plug from the map sensor produces no change to the reading or tickover of the engine.

I'm towing the car back to my garage this week so that I can investigate further but I would greatly appreciate any advice or possible pointers before I start.

Thanks in advance

Justin

KW808 OBD2 Code Reader

Welcome to the forum mountainman

Current error codes that wont clear are -
P0108 - manifold absolute pressure or barometric pressure circuit high input.


In the last few weeks in an effort to resolve the problems (and under the advice of the chaps from the AA) I have changed the following items -
MAP SENSOR
Coil pack
Spark plugs
throttle body
(All parts fitted were brand new)

One thing I did notice is that my mac tools diagnostic unit has live a live data function and when revving the car the manifold pressure is static, no change whatsoever. Even removing the plug from the map sensor produces no change to the reading or tickover of the engine.

If changing the MAP sensor didn't allow the fault to clear, then check the wiring all the way to the ECU for that sensor.
You can use your live tools to monitor the signal while you wiggle wires and clean connectors with some Contact Clean

p0609 - control module vehicle speed sensor output b malfunction.

Could be ECU trouble these can be tested, but check connections first.

And in addition to the above I have also sealed off the washer jets to prevent the "drip" problem

Was there any evidence of previous dripping?

Thanks for your prompt reply, Although all connections seem clean and free from corrosion I cant rule out water having previously having got at the ecu as the battery cover which also covers the ecu connectors is missing, and her problems only started after all the heavy rain we've been recently having
I'll have the car here soon and will give the loom a proper check through and will fit another new map sensor just to be sure.

out of curiosity, I have seen plenty of breakers selling complete second hand ecu kits (including keys and transponder pickups etc) but have yet to see one from an automatic car. Would you know if the ecu's from a manual are compatible with an automatic car.

Thanks once again for your help

mountainman wrote:Thanks for your prompt reply, Although all connections seem clean and free from corrosion I cant rule out water having previously having got at the ecu as the battery cover which also covers the ecu connectors is missing, and her problems only started after all the heavy rain we've been recently having

Sounds like something got wet, there is another C3 owner who had similar problems with a missing battery cover.
Citroen C3 lost my power steering and speedo


You can find BBA Reman (via their ebay store) who offer a service to test the ECUs.

I have seen plenty of breakers selling complete second hand ecu kits (including keys and transponder pickups etc) but have yet to see one from an automatic car. Would you know if the ecu's from a manual are compatible with an automatic car.

I don't know if the ECUs are different, but you can be very sure the programming in them is different.

Thanks once again for your help

No problem, please keep us updated on how things are progressing, thanks.

Hi just a quick update,
car is back running fine as of today, problem is I never actually found anything physically wrong so have a bad feeling that this problem might reoccur.
Fitted another new map sensor today but made no difference. same code same static map reading on diagnostic (36" Hg), codes would not clear.
Pulled every connector under the bonnet apart and checked for corrosion or water ingress then cleaned thoroughly and refitted. No difference again.
checked all connectors behind glovebox and again cleaned and refitted. no difference.
I was just about to give up for the day when with the ignition on I removed the battery live connector and refitted it quickly.
The throttle body (which is a brand new one) started to make a loud whistling noise so in my panic I quickly pulled the plug out of it and only then thought about disconnecting the battery
With the battery disconnected and ignition now off I refitted the throttle body connector, then the battery, and run the diagnostic hoping that I hadn't done any damage. Immediately I could see the Map sensor reading was different and was fluctuating slightly this time the codes cleared first time
Don't know what actually happened but it seemed that the sudden connecting and reconnecting of the battery seemed to spark something back into life.
Since then the car has run perfect, I just wish that I could actually say that I found the culprit so that I could have confidence in using the car in future.
Thanks

Thanks for keeping us up to date. It good to hear how the jobs progress or not. Hopefully yours is fixed for good.