Vauxhall Corsa 1.2 Z12XEP 2004 - Auto box control malfunction, codes U2108, P1120 & P1725 - Fixed #
Posted by John Kennard on January 10, 2011, 3:03 pm
Year of Manufacture *: 2004 ( Optional ) Engine Code or CC: Z12XEP
Hi all, had a number of these lately but still needing to grow in knowledge and experience the above vehicle has lost all gears and won’t even start now blocked by auto fault. Scanned with Vaux Com. and codes as follows.
U2108 - CAN-Bus No Communication with ABS (Anti-Lock Brake System) (04) - Not present
P1120 - Accelerator Pedal Position Signal Range/Performance (08) - Not present
P1725 - Shift Motor Speed Signal (0B) - Present
Cleared codes a number of occasions but the dash continues to flash F (fault in box) Checked data and voltage is seen on accelerator pedal. I also can see the gear selection taking place D (drive) N (Neutral) R (Reverse) Not sure about the CAN-Bus Signal to ABS but the ABS module has no recorded codes. Also the shift motor shift signal? Does anyone have more experience on these to know what to check next Please.
Hi Took the plunge as Code P1725 Shift motor speed signal (OB) - Present was permanent, also the advice of my local dealer was the motors pack up, so fitted new motor unit only four bolts & £420.00 +VAT. The old unit when removed was stuck in 3rd gear. After clearing the codes the vehicle started and now drives perfectly. They advised it may need to go on tech 2 and go through a gear learn process but it drove perfectly.
Did a Ford Fiesta the day before, when after driving a few miles would stick in one gear, a couple of mates around the corner just come out of a dealership have the Ford IDS, They carried out a software update & gear learn but made no difference. We fitted another expensive motor unit to this and that now drives perfectly.
Attended another customer breakdown after his battery went flat on a Vaux Corsa, the Easytronic flashed F (Fault) on the dash and would not go into gear, we attended and cleared out ABS comms & 2 Wheel speed sensor codes and the gearbox responded and drove perfectly.
Having had nothing to do with these semi auto, easytronics before, apart from viewing them on services I was quite chuffed to have cured 3 in 4 days of each one occurring.
Having talked to the dealership and my Ford mates the gearshift motors appear to be the biggest problem. Our local Vaux dealer had them sitting on the shelf. They come as a pair mounted on a plate and one does the neutral shift while the other moves the gearshift and are either geared together (Vauxhall) or by linkage (Ford).
The Clutch is operated by a seperate electro hydraulic module which in most cases has the ECU attached, it is also good practice to check all electrical connections as on the Ford Fiesta we did, we found a number of green terminals on various connectors. This unit is situated out front of the gearbox near the N/S/F wheel and quite exposed, although the connectors did not cure the problem they may have gone on to be problomatic after fitting the motor unit. Hope this helps someone in the future. John Kennard.
Re: Fixed #
Posted by phil kingdon on February 7, 2011, 9:11 pm, in reply to "Fixed #" Phil Kingdon
Hi john, Thanks for tips, we have similar fault on corsa arrived today, took quite a while to get comms with solus, forgot to bring discovered codes home with me but will check tommorow against your list. Not sure if this customer wants to repair yet, 02 car,100k miles, so he is worried about costs! Will post again tommorow, cheers, phrom fill.