New ECU apparently... Fault code P1680

AndyJ

My car went in Limp home mode again on Sunday, second time in the last four months i think, EML light has been on quite a few times over that period.
Had a tech2 done this morning and the guy at Vauxhall said its bringing up a P1680 fault code (not current/ present) which is something to do with an accelerator sensor or something. He recons that 'in their experience' these never tend to go faulty and its more than likely the ECU is knackered (could explain some of the other wierd electrical problems i've been having). The test steps for that fault code are 40 pages long and Vaux would have to do all these, at a cost of £160, to find out exactly what the problem is!
Basically i need a new ECU which i'm less than happy about because i'll need to get it remapped again which is more money. I've got the DBilas inlet manifold so i presume this will need setting up again??

Does anyone have any experience of this fault code? I can't remember the exact wording he used to describe what it meant. I really don't want to be forking out for a new ECU from Vaux plus another remap! 🙁

slimvince

IIRC - have a look and search at the vx220-forum. Either the accelerator pedal, ECU, the interconnecting cable or the connectors are faulty.

Edit: nope, had a check at the vx220-forum, the error code I was having is P1271. Not unlikely though you have the same problem - try cleaning all the connectors. On the vx220 there is one on the accelerator pedal, one on the ECU and finally one in between cause the loom is split in two halves.

vocky

P1680 - Accelerator Sensor Voltage Low
The control unit recognises the malfunction of the circuit via an internal evaluation logic.

a common problem is the throttle pedal plug gets a bad contact, either that or a new throttle pedal sensor is needed :roll:

markv

A new ECU? Hmm, interesting. I've been torturing the one on my test bed quite a bit (did some wrong wiring which put a bit too much amps through the wrong pins). ECU still working completely happy 🙂 They seem to be quite resilliant.

I would check for wireing, especially check all the grounds are correctly connected (the seperate wire on the ECU is the only ground it has!). There should be two more from the wiring loom going to the engine itself.

If the accelerator is really broken you can also try and measure the voltages (easiest with tech2 or related product). You should see one voltage going down and one going up when pressing the pedal. Could give you an indication if 1 connection is broken or more...

Mark