2009 Fiat Panda 1.1 - P0202 and possible earthing problem

[Iddingtons]

Hello all,

I tried this in the Fiat section and got no help, so thought I'd try here!

I have been helping to fix a friend's Fiat Panda but we're stuck.

It started off with an engine warning light and a P0202 fault code on injector 2. So at the weekend we swapped injectors 2 and 3 to see where the fault reappeared so we could tell if it was the injector or wiring/ecu.

We've test driven the car and there are no dash warning lights as yet and it runs great...only now when I scan the OBD I get two faults under the Delphi electric steering. C1003 (alternator) and C1004 (vehicle speed from CAN). I cleared them but they reappear at next key on.

We did disconnect and check the ecu connection, plus jiggle the wiring looking for any obvious issues after we swapped the injector in case the wiring was the issue...could that have somehow caused the two new faults?

Is there a common earth that's a likely culprit?

The battery shows -12.5v and a little over 14v when running so I don't think it's a weak battery.

Help, we're stuck!

Thanks,

David.

[Penelope Stopit]

Iddingtons said:

Hello all,

I tried this in the Fiat section and got no help, so thought I'd try here!

I have been helping to fix a friend's Fiat Panda but we're stuck.

It started off with an engine warning light and a P0202 fault code on injector 2. So at the weekend we swapped injectors 2 and 3 to see where the fault reappeared so we could tell if it was the injector or wiring/ecu.

We've test driven the car and there are no dash warning lights as yet and it runs great...only now when I scan the OBD I get two faults under the Delphi electric steering. C1003 (alternator) and C1004 (vehicle speed from CAN). I cleared them but they reappear at next key on.

We did disconnect and check the ecu connection, plus jiggle the wiring looking for any obvious issues after we swapped the injector in case the wiring was the issue...could that have somehow caused the two new faults?

Is there a common earth that's a likely culprit?

The battery shows -12.5v and a little over 14v when running so I don't think it's a weak battery.

Help, we're stuck!

Thanks,

David.

You may well have disturbed bad wiring when swapping injectors and waggle testing the wiring
The fact that you swapped injectors and the engine fault went away points to a wiring fault, if that injector was faulty there would still be a fault
If apart from the injector P0202 fault code on injector 2 there were no other faults showing when you started the injector swap, everything suggests there is a wiring fault
First take a look to see if there is an engine plug that could be playing up and causing the faults or a short on the engine wiring loom, look for loose earths and positives near to the engine (there may not be any engine loom earth points on the engine apart from the main thick earth from the battery

Should you have no joy with the above, working at injector 2 as that was the injector originally showing a fault, using a multimeter carry out a waggle test while having the meter set for continuity testing connected between one injector wire and its termination point at the ECU or possibly the relay that may power it and then repeat this test on the other injector wire (you may need an engine diagram)
Waggle away all along the loom when the multimeter is connected

Carry out a very similar test between the wiring at the injector and earth to see if the loom is shorting out to earth somewhere, you may well have removed a short when disturbing the loom earlier, look very closely at the loom, clean oil of it if need be so that you can see any rubs

Should you not find the fault you will need to carry out a similar test on the Delphi electric steering circuit wiring wherever that goes from and to

I reckon the fault may well show up when carrying out the waggle test on the injector 2 wiring from injector to ECU

Edited by Penelope Stopit on Monday 14th May 12:53

[Iddingtons]

Penelope Stopit said:

You may well have disturbed bad wiring when swapping injectors and waggle testing the wiring
The fact that you swapped injectors and the engine fault went away points to a wiring fault, if that injector was faulty there would still be a fault
If apart from the injector P0202 fault code on injector 2 there were no other faults showing when you started the injector swap, everything suggests there is a wiring fault
First take a look to see if there is an engine plug that could be playing up and causing the faults or a short on the engine wiring loom, look for loose earths and positives near to the engine (there may not be any engine loom earth points on the engine apart from the main thick earth from the battery

Should you have no joy with the above, working at injector 2 as that was the injector originally showing a fault, using a multimeter carry out a waggle test while having the meter set for continuity testing connected between one injector wire and its termination point at the ECU or possibly the relay that may power it and then repeat this test on the other injector wire (you may need an engine diagram)
Waggle away all along the loom when the multimeter is connected

Carry out a very similar test between the wiring at the injector and earth to see if the loom is shorting out to earth somewhere, you may well have removed a short when disturbing the loom earlier, look very closely at the loom, clean oil of it if need be so that you can see any rubs

Should you not find the fault you will need to carry out a similar test on the Delphi electric steering circuit wiring wherever that goes from and to

I reckon the fault may well show up when carrying out the waggle test on the injector 2 wiring from injector to ECU

Edited by Penelope Stopit on Monday 14th May 12:53

Thanks for the reply.

That's right, when we started the injector swap no other faults showed up. They only appeared after we had moved the wiring about and waggled everything.

I believe there is a second body mounted earth beneath the battery so will take a look at that, plus check the wiring as you suggest. I'll see if I can track down a wiring diagram for it. I have a suspicion the fuel rail wiring has a spliced join that's failed within the loom but not sure where to look and was trying to avoid unwrapping the whole thing.

I hate hunting for wiring faults, be easier if I could just plug in a new loom but that seems extreme for what is probably one wire! ha!

[GreenV8S]

It seems common for injector supplies to have a single shared positive supply with a splice connecting each injector, and separate switched negative lines for each injector (or each switched injector bank). In this case the splices would be close to the injector at the point the injector's wiring comes out of the common loom.

[Iddingtons]

GreenV8S said:

It seems common for injector supplies to have a single shared positive supply with a splice connecting each injector, and separate switched negative lines for each injector (or each switched injector bank). In this case the splices would be close to the injector at the point the injector's wiring comes out of the common loom.

OK, I'll start at the injector number 2 and work towards the ECU.

Thanks!