C5 Mark iii 2009 2.0 hdi automatic

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

chasqui
Donor 2020
Posts: 58
Joined: 02 May 2009, 12:02
x 3

C5 Mark iii 2009 2.0 hdi automatic

Post by chasqui »

Was driving on the motorway doing just under 70 mph when the car threw a fault message at me. Loud boing followed “gearbox faulty” message and service light came on.

After a few seconds the gearbox faulty sign disappeared but the service light remained,

I noticed the snowflake sign and the S symbols flashing and the dashboard showed D6 indicating I was still in 6th gear.

The car drove ok but upon deceleration I noticed it remained in 6th gear. I tried manually shifting down but nothing happened.

I managed to limp home. When stopped I managed to shift into reverse but car jumped as it went into gear.

Putting it in Drive caused it to go straight into 3rd gear.
So, it will go forward but doesn’t shift out if 3rd gear though it will go in reverse, albeit jumping into gear.

Any ideas? I will try read off any faults with Diagbox tomorrow.

A few months ago a similar problem which caused the engine to cut out and the car to give the gearbox faulty message was due to a faulty engine compartment fuse box. This was replaced with a new one and this cured that fault.

The vin number is VF7**************[VIN obfuscated, can be read by forum staff]

Thanks in advance!
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26024
Joined: 15 Sep 2015, 19:38
x 2980

Re: C5 Mark iii 2009 2.0 hdi automatic

Post by GiveMeABreak »

There's a load of codes for these - so if you can get the fault codes tomorrow from Diagbox, I should be able to get some info for you.
chasqui
Donor 2020
Posts: 58
Joined: 02 May 2009, 12:02
x 3

Re: C5 Mark iii 2009 2.0 hdi automatic

Post by chasqui »

So this morning I plugged in diagbox.

Results as follows

ECU:
P0338 and P0337 engine speed signal. INTERMITTENT
P1351 Pre heat relay circuit. INTERMITTENT

GEARBOX:
P0727 Fault on engine speed info not received by the CAN (Engine ECU). PERMANENT
Also worth mentioning Converter status was “Locked up or Closed” in Ratio 6
SUSPENSION:
U1208 Fault invalid data from the engine ECU INTERMITTENT
U2005 Triggering (vehicle speed receipt anomaly) PERMANENT

DEFLATION DSG
U1213 Fault in the vehicle speed information received by the CAN from the ABS or ESP ECU. PERMANENT

I took all the codes before starting the engine this morning. When I did, the car runs normally and no faults or lights in the dashboard! Though I have not cleared any of the faults mentioned.

So, wild guess, some dodgy sensor somewhere to do with the speed reported by the gearbox?

Thanks in advance
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26024
Joined: 15 Sep 2015, 19:38
x 2980

Re: C5 Mark iii 2009 2.0 hdi automatic

Post by GiveMeABreak »

Ok, so may be better news initially in that all these faults with the exception of the pretty standard glow plug fault are related to speed anomalies. As the speed data is essential for many components (Engine ECU, Suspension, ABS, Gearbox etc.), a fault here will have a knock-on effect.

The most likely suspect is the Engine Crankshaft Sensor / Speed Sensor. In simple terms, it's a Hall effect sensor that, as the teeth of the crank pass the magnetic tip of the Crankshaft Speed Sensor, it sends a low or a high wave (voltage) when it detects either a tooth or a gap in the Crankshaft. So P0337 and P0338 are saying there are too many low signals one minute and too many high signals the next - which would indicate that the sensor is knackered and sending the wrong data.

I would not ignore this as you have seen, although the car may run ok for now, this will likely get worse and can result in bigger problems. It certainly won't do the gearbox any good or the engine with all the jerking that may increase.

The Sensor is located at (4) below, and is part number: 1920GJ, and costs £62.14 direct from Citroen inc. VAT if you want an original one.
X7  Crank sensor.PNG
I think that's your best starting place. Once you have the sensor replaced, you should clear the faults, then take the car for a good run and that should clear the other related faults all being well. Any remaining faults ca be looked at knowing that the crankshaft sensor has bee replaced.

P0337: Engine speed signal: Signal not coherent. The number of teeth seen on the target of the engine speed sensor is too low on 1 engine rev. The fault is forwarded after 2 engine revolutions.

Down-grade modes whilst fault present: Switching on of the warning lamp and/or warning message.

Complaints Likely: Starting problem, Jerking/stalling

Suspect Areas: Engine speed sensor target, Engine speed sensor, Electrical harness
Connector

P0338: Engine speed signal: Signal not coherent. Engine speed signal too close: too many teeth over one crankshaft revolution. Too many teeth are seen on the engine speed sensor target over 1 revolution. The fault is forwarded after 2 engine revolutions.

Down-grade modes if fault present:Switching on of the warning lamp and/or warning message.

Complaints likely: Starting problem, Jerking/stalling.

Suspect Areas: Engine speed sensor target, Engine speed sensor, Electrical harness, Connector.
chasqui
Donor 2020
Posts: 58
Joined: 02 May 2009, 12:02
x 3

Re: C5 Mark iii 2009 2.0 hdi automatic

Post by chasqui »

Marc, as always, you’re superb

Many thanks. Sensor on order being delivered tomorrow
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26024
Joined: 15 Sep 2015, 19:38
x 2980

Re: C5 Mark iii 2009 2.0 hdi automatic

Post by GiveMeABreak »

No worries - Here's a brief illustrated guide on how to replace it that I've put up in the 'How To' section.

viewtopic.php?t=64437
chasqui
Donor 2020
Posts: 58
Joined: 02 May 2009, 12:02
x 3

Re: C5 Mark iii 2009 2.0 hdi automatic

Post by chasqui »

All fitted. Faults cleared. Done about 20 miles. So far so good!

Thanks again Marc!
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26024
Joined: 15 Sep 2015, 19:38
x 2980

Re: C5 Mark iii 2009 2.0 hdi automatic

Post by GiveMeABreak »

No worries, glad that is sorted for you.
vlax
Posts: 2
Joined: 04 Feb 2021, 21:55

Re: C5 Mark iii 2009 2.0 hdi automatic

Post by vlax »

Hello everyone,
I have similar problem with my Peugeot, same engine and automatic gearbox,.
"Gearbox fault " "snowflake", "S" "ESP" light , for no reason in drive. I stop and turned off car, and after starting again, everything normal. (I have car 2 years and that's happened 2 times)
Today I went to change oil in gearbox, and diagnostic shows
- Engine P0336, P0337 and P1351 codes
- Gearbox P0727
Do your thinks that change the sensor (4) from previous post solve some problem or codes

Thanks