1.7 Diesel Astra H Problems

[Jimbob]

A friend has an 05 1.7 DTL Astra H, when driving, it goes to limp mode, but revs stay at about 4000 plus!

Done a code read and have


P1120 - Accelerator Pedal Position Sensor 1 and 2 Signal Incorrect Ratio
(52)  - Not present

P1122 - Accelerator Pedal Position Sensor 1 and 2 Signal Incorrect Ratio
(52)  - Not present

U2103 - CAN-Bus Circuit Malfunction
(06)  - Not present

from the engine,

and from the ABS..
C0242 - Engine Torque Request Signal Range/Performance
(71)  - Not present

C0237 - Accelerator Pedal Position Sensor Incorrect Signal
(71)  - Not present

U2100 - No Communication with CAN-Bus (High Speed)
(00)  - Not present

C0800 - System Voltage Low Voltage
(03)  - Not present


I think a new pedal position sensor is probably the way to go, but a local garage have suggested they have seen it before, frequently and needs a new (expensive ECU).

any thoughts?

[tigers_gonads]

There is something that goes tits up with the ecu's on a regular basis.

Iirc, they get dry joints on the pcb.
Something to do with the mounting of the ecu case.

I believe that the pcb can be removed attacked with a soldering iron with great sucess 

[Jimbob]

Hmmm looking round it could be..

Pedal Sensor
Throttle Body sensor
Wiring between these
or the ECU Itself.

booo.

[omegod]

Worth throwing a pedal/throttle body sensor from a scrapper at it, if it doesn't work stick em on the bay.

My money would be on the pedal sensor personally.

[serek]

there company in derby who can test ecu for any damage for about £60
http://www.ecuelectronics.co.uk/

how many of those codes come back after clear them??

[iainb]

Jim, The CAN network has gone down. What you need to do is get a wiring diagram and follow the CAN high and CAN low wires and establish where the brake is first .These wires are braided together.

[Andy B]

....
and establish where the brake is first .....

That the pedal in the middle isn't it! 

[Jimbob]

All codes went, havent rechecked what has come back yet.

I hate electrical issues, especially intermittant ones

[Marks DTM Calib]

Looks like something had a wobble on the high speed CAN line, cause could have been low battery voltage so check alternator and battery charge state

[Jimbob]

It had a new alternator (unrelated) last year, so suspect that may be an old code.

will prob reread tomorrow.

[Jimbob]

Car has behaved since I read and cleared codes.

Checked it again last night, and the only ECU with a code, was the ABS one...

C0800 - System Voltage Low Voltage
(03)  - Not present

back again.

So You may well be onto something Mark.

[Jimbob]

Saw it again yesterday, and same again, low voltage recorded in the ABS Ecu..

car has been fine since....

[Marks DTM Calib]

Check electrical feed to the ABS unit, main pos supply being the first call (seem to recall it is via a large voltage distribution fuse)