C4 Grand Picasso Reporting Gearbox and Electronic brake fault

[rudger]

HI all,

First time poster please go easy on me lol.

My 2014 Citroen C4 Grand Picasso is currently in a local garage with errors reporting "Gearbox Fault: have the vehicle repaired" Followed by Parking Brake fault have the vehicle repaired"

I have had a replacement battery installed - as old battery was failing and still getting the same problem

The Garage has cleared all faults on ECU, and completed BSI Reset and no improvement

I have managed to get the car scanned using Diagbox and have the following errors

Engine management ECU HDI_SID807_BR2 (1 Faults)
P1352 Engine preheating.
Properties
Cause Local
Status Intermittent
Nature of fault Fault on the pre-heating relay or glow plugs

Anti-lock Braking System (ABS) or Electronic Stability Program (ESP) ESP90 (1 Faults)
U1109 87 Communication with the automatic gearbox ECU
Properties
Status Permanent
Characterisation of the fault No signal

does anyone have any suggestions where to go next?

[GiveMeABreak]

You can pretty much ignore P1352 (P1352 is diagnosed as a Fault on the pre-post heating relay circuit: Relay not controlled / plugs controlled), as that is a common one and won't be anything to do with this issue.

Your other issue is generally explained below - there is no comms with the automatic gearbox ECU, so needs investigation. Start with the ECU connections - make sure the plug has not been disturbed by any recent work or a pothole. Check that the connector pins are not broken and all the obvious things first.

Fault Code:	U1109 87
Description of Fault:	Communication with the automatic gearbox ECU: No signal. Communication with the automatic gearbox ECU: Information not received. The time for recording the fault code is 500 milliseconds
Conditions for Fault to clear:	Ignition on (For at least 30 seconds)
Downgrade Modes whilst Fault is active:	Deactivation of the hill start assistance function Deactivation of the "Stop and Start" function Deactivation of the descent control system Switching on of the warning lamp and/or warning message: "Stop and Start" warning lamp "SERVICE" warning lamp Descent control system fault warning lamp
Symptoms:	Poor behaviour of the vehicle on braking Malfunction of the descent control system
Suspect Areas:	Automatic gearbox Connectors Intersystems CAN

[rudger]

Thanks @GiveMeABreak

any ideas which connectors (and Locations) I should be checking first. I went through the fuse box earlier and checked all fuses and they were all fine. if it is any help my vin is
VF7**************[VIN obfuscated, can be read by forum staff]

Thanks in advance Rudger