C4 Grand Picasso won't start. Gearbox fault?

[emteell]

Our C4 Gran Picasso 2011 (clutchless gearbox) will no longer start out of the blue, though a couple of days earlier there had been an engine fault warning which went away again. Called the RAC. They came but they couldn't get it started either.

I'd be grateful if anyone out there can tell me which lines, if any, in their "diagnostic" report to focus on. Nearest Citroën garage is 15 miles away. Thanks in advance.

DTC: P1718,Gear selector signal
On going fault with vehicle. Citroen C4 Grand Picasso FWD.
Stuck in gear, automatic gearbox.
Non roadside fix.
Requires workshop attention.
Attempted battery disconnect, code reset and recalibration of gearbox. No success
Technical details
Diagnostic codes
GEARBOX

Name:GEARBOX - AL4
DTC:7181,unknown
9HR - SID807

Name:9HR - SID807
DTC:P1445,The quantity of additive injected into particle filter has exceeded the maximum threshold. The particle filter must be changed.
DTC:U1209,CAN: One of the parameters present in a data stream sent by the gearbox ECU is invalid
DTC:U1218,CAN: One of the parameters present in a data stream sent by the BSI is invalid
DTC:P0265,Injector cylinder 2
DTC:P16A3,Monitoring fault on the starter inhibitor (level 2)
GEARBOX - AL4

Name:GEARBOX - AL4
DTC:7181,unknown
GEARBOX - CFC300P

Name:GEARBOX - CFC300P
DTC:P1718,Gear selector signal
BODY COMPUTER - DIAGNOSE

Name:BODY COMPUTER - DIAGNOSE
DTC:5FF,Unexpected re-initialisation fault coming from the BSI
GEARBOX

Name:GEARBOX - CFC300P
DTC:P1718,Gear selector signal

[mickthemaverick]

The first thing I'd do is check the gearbox connectors for clean contacts and fully plugged in.

[RichardW]

The gear selector lever is a common fault on the semi autos, but yours looks like a proper auto. However as you have a code for it I would start there, they are plug and play, and cheap enough used to just try - but make sure you get the right one.

[emteell]

Apologies for late reaction. I've ticked all the boxes to get notifications by email but as I hadn't received any I assumed my request had not yet gone live...

Thank you @RichardW and @mickthemaverick
Even though it looks like an automatic our understanding is that it is a semi-automatic.

@RichardW
Can you provide any guidance on how to search for the correct gear lever part number, if I were to go that route?

@mickthemaverick
Sounds like what you are suggesting should be my first step but where do I look for the gearbox connectors? Are they easy to access?

Thank you again both

I found an older posting on this forum (C4GP Gearbox fault + Parking brake fault) that mentioned the gearbox ground cable (9677717680) as a possible cause. Might that be connected to my issue?

[mickthemaverick]

The earth strap is well worth checking as it is a known fact that they do corrode and become high resistance. The connectors can be on the top or on the back, not usually underneath but you never know. Just a matter of possibly using a torch to follow any wiring near the gearbox and see what you come across.

[RichardW]

I thought it might be a semi auto, but the diag report says AL4, which isn't, but also isn't necessarily correct!

Does it have a P position on the selector?

[emteell]

Hello @RichardW, No it doesn't have a P position on the selector. The parking brake engages automatically when the engine is switched off.

I managed to get it started last week after disconnecting, waiting a wile, reconnecting the battery and waiting again, even though the dashboard was signalling first a gearbox fault and then a parking brake fault. We then took it for a test drive with no issues. All the gears worked fine. Whatever the problem is, it is looking more likely to be electrical/electronic, resulting in erroneous error messages, rather than gearbox related.

@mickthemaverick Thank you for your suggestion. I spoke to a Citroen specialist mobile mechanic who independently suggested that it is likely to be a a corroded cable or cables within a loom but that it is not straightforward detective work. I'm not even sure where to start looking. Is there an archive of photos on this forum or elsewhere you can point me towards?

[mickthemaverick]

This site has a couple of pictures showing the gearbox with the wiring in place which might help: https://www.proxyparts.com/car-parts-st ... /21755529/

[emteell]

Thank you @mickthemaverick.

Still off the road.

After more intermittent starting I did a BSI reset. I was able to drive to the garage for the MOT but am still apprehensive about using the vehicle.

I've acquired a VXDIAG SE with the PSA licence. It mostly overlaps with the RAC report (cf my first post) but is reporting additional detail and some additional faults. The one that grabs my attention in view of others' comments about wiring issues is:

"P0265 Injector 2 control/Local/Intermittent "Short circuit between two wires"". Which two wires? Where to start looking?

I'd really like to know which if any of the 19 faults reported here are most likely to be causing the dashboard errors (gearbox/parkingbrake) and the refusal to start, and whether there are any I can safely ignore. I can provide more detail for any of the faults from the report.

As ever I'd be grateful for any pointers.

Engine management ECU HDI_SID807_BR2 (12 Faults)
P1445 Additive adding/Local/ Permanent "The quantity of additive injected into the particle emission filter has exceeded the maximum threshold. The particulate emission filter must be changed" KM284480
P0265 Injector 2 control/Local/Intermittent "Short circuit between two wires" KM287734
P16A3 Control unit/Local/Intermittent "Monitoring fault on the starter inhibitor (level 2)" KM284834
U2000 Intersystems CAN/Distant /Intermittent "Request for principal wake-up of the ECU not plausible or absent" KM287927
U2118 Intersystems CAN/Distant /Intermittent "Request for partial wake-up of the ECU not plausible or absent" KM287927
U0073 Intersystems CAN/Distant /Intermittent "CAN in error" KM287927
U1218 Intersystems CAN/Distant /Intermittent "One of the parameters present in a datastream sent by the BSI is invalid" KM287865
U1218 Intersystems CAN/Distant /Intermittent "One of the parameters present in a datastream sent by the BSI is invalid" KM287865
U1209 Intersystems CAN/Distant /Intermittent "One of the parameters present in a datastream sent by the gearbox is invalid" KM285239
P1AA2 Voltage maintaining device /Local/Intermittent "Internal electronics fault" KM0
P050B Starting monitoring /Local/Intermittent "Starting time too long" KM287942
P0500 Intersystems CAN/Distant /Intermittent "Speed information wrong or absent" KM 287927

Anti-lock Braking System (ABS) or Electronic Stability Program ESP81 (1 Faults) (ESP)
U1309 Fault: absence of communication with the automatic gearbox ECU /Distant /Intermittent "No signal"

Automatic or piloted manual gearbox CFC300P (6 Faults)
P1718 Gear lever signal fault/P1718 Gear lever signal fault /Local/Intermittent "Coherence" KM 287865
P1800 Gearbox programming incomplete or not carried out fault /Local/Intermittent "Not characterised" KM 287865
U2000 Receiving of the main triggering request information fault /Local/Intermittent "Not characterised" KM 287927
U1108 Fault in communication with the engine management ECU /Distant/Intermittent "No signal" KM 287927
P1716 Gear lever signal fault /Local/Intermittent "Short circuit to positive or open circuit" KM 287927
U1003 Fault in communication on the CAN /Local/Intermittent "No signal" KM 287927

Automatic gearbox electric control ECU No dialogue
Power steering No dialogue
Pneumatic suspension No dialogue
Diesel additive pump POMPE_MUX_TI
UNDER-INFLATION DETECTION No dialogue
Dynamic headlamp height adjuster No dialogue
Battery charge status control unit BECB_GEN2
Electric secondary brake FSE
Lane wandering alert No dialogue
Engine wiring housing No dialogue
Trailer relay unit No dialogue
Airbags and pretensioners ECU SAC_AUTOLIV
Windscreen wiper MOTEV
Parking assistance AAS
Controls under the steering wheel VCCF
Air conditioning CLIM_REGULEE
Instrument panel COMBINE
Separate instrument panel No dialogue
Audio amplifier No dialogue
CD changer / External CD player No dialogue
Telematic unit (RTx) or audio-navigation No dialogue
Radio No dialogue
Hands-free Kit / Portable Unit No dialogue
Voltage maintaining device DMTC
Anti-theft alarm No dialogue
Seat driver position memory module. No dialogue
Passenger door module No dialogue
Driver's door module No dialogue
Interior ambiance lighting control unit No dialogue
Rain and brightness sensor No dialogue
High frequency receiver No dialogue
Service module / Independent telematic unit No dialogue