Technical ECU/ABS Module Fault, Car Won't Start

[MaksW]

Hi all, I've been skimming these forums a bit but haven't been able to find an answer to my question. Im the owner of a 2007 Fiat Punto 1.2 (first car). Its a great car to drive though there have been a few issues. Most recently the car will simply not start, and the immobiliser warning light turns on on the dash.

To this point I have:
Checked the earth cable and used my starter cables to connect the gearbox to the battery,
Checked all fuses and relays for damage,
Checked the key battery,
Removed the car battery and charged it overnight,
Removed the immobiliser fuse and tried to start the car,
Connected the starter motor directly to the battery,
Tested power in all fuses with ignition on.

My findings suggest that it is not an immobiliser issue (car won't crank with key) but I admit I dont have a spare key to test it, or a starter motor issue (motor works when I wire it direct to the battery). What I have been able to find is that 3 fuses (F30,F33,F34) have no power with the ignition on, no check engine light pops up with ignition, and I cant connect to engine with OBD. This to me suggests the ECU is not working. I did find a thread where something similar was caused by a faulty Abs module, but I dont know how to check it. Anyways my question now is whether its the Abs or Ecu (or something else I didnt think of), and what else I can check or do.

Thanks in advance

 

[The Panda Nut]

If the immobiliser light is on it suggests it is an immobiliser issue. Im afraid Im no expert. The system relies on key and ecu being able to read each other. There are receivers and aerials involved in the vicinity of the steering column I believe. There has been a few such things discussed on here so search on immobiliser on all forums and you may get some information to help you. O e[xect someone will be along to give better advice soon, Good luck.

 

[puntodad19]

Impressive mileage

 

[MaksW]

Impressive mileage

Its kilometers by the way, but yeah its got a bit on it

 

[MaksW]

Hi all, I've been skimming these forums a bit but haven't been able to find an answer to my question. Im the owner of a 2007 Fiat Punto 1.2 (first car). Its a great car to drive though there have been a few issues. Most recently the car will simply not start, and the immobiliser warning light turns on on the dash.

To this point I have:
Checked the earth cable and used my starter cables to connect the gearbox to the battery,
Checked all fuses and relays for damage,
Checked the key battery,
Removed the car battery and charged it overnight,
Removed the immobiliser fuse and tried to start the car,
Connected the starter motor directly to the battery,
Tested power in all fuses with ignition on.

My findings suggest that it is not an immobiliser issue (car won't crank with key) but I admit I dont have a spare key to test it, or a starter motor issue (motor works when I wire it direct to the battery). What I have been able to find is that 3 fuses (F30,F33,F34) have no power with the ignition on, no check engine light pops up with ignition, and I cant connect to engine with OBD. This to me suggests the ECU is not working. I did find a thread where something similar was caused by a faulty Abs module, but I dont know how to check it. Anyways my question now is whether its the Abs or Ecu (or something else I didnt think of), and what else I can check or do.

Thanks in advance

To anyone who finds this in the future, the issue turned out to be a damaged 12V power cable for the ECU. Repaired the cable and the car now runs fine again.

 

[puntodad19]

Glad you found the problem.

As a matter of interest, which cable going to which pin etc...and where was the cable broken please ?

 

[paulharpur1978]

Having a similar issue here myself. Just scanned the car and I have voltage issue to ECU. Could you update on the cable color and location of damage?

 

[varesecrazy]

Having a similar issue here myself. Just scanned the car and I have voltage issue to ECU. Could you update on the cable color and location of damage?

@MaksW

 

[GrandePunto PL]

Don't wait for answer. Do it yourself. Use schematic diagrams (this is how you fix electrical issues).
https://4cardata.info/elearn/199/2/199000000/199000000/199000000/199002842