Hi All

My Grande Punto model '07 1.4 8v petrol can crank, but it never starts.

I have the following error codes using FiatECUscan program.

Error codes:
P0638 Motorised Throttle
P0657 Congruence of main relay battery voltage upstream/downstream
and sometimes
P1687 Motorised throttle (Stop learn)

Symtoms:
-No sparks at sparkplugs, when cranking with key. Sparks can be generated by manually actuating them using FiatECUscan tool.
-Motorised throttle is never moved by ECU, even when issuing a relearn throttle position command from FiatECUscan.

I have tried the following:
- Battery is fully charged, same issue
- Tested MAR senser OK
- Crank sensor OK
- Fuel pump is running OK
- Injection ok
- Lamda senser OK
- Tried different ignition key, same issue
- Tested the Motorized throttle by tapping pin52 and pin57 at ECU connector with ground/+12V. The throttle opens nicely and the spring close it again.
- I can read out throttle position with FiatECU scan by manually actuating the throttle.
- I can actually start the car by first actuating the sparkplug with FiatECUscan and then cranking the car on with the key, the throttle still does not move and if I turn off the car and tries to restart it cannot start, until the coils for the sparkplug has been manually actuated by FiatECUscan tool.



My best guess is the change the ECU or maybe the throttle body, but they are expensive parts.

Do you have any ideas to what I could test to get closer to solving the issue?


Thanks in advance,

Mgarb

SOLVED:

The issue here was one of the 30A relays to the ECU that was malfunctioning.

Changing the relay solved the problem.

Best Regards,
Mgarb

Hi I'm having same issue could you let me know where the relay is that needed changing please

Hi mhaley78

I believe it was relay T7 I changed in the fusebox to get it functional again.

Best Regards
mgarb

Here is a picture showing the location of the T7 relay in the fusebox.




Hope you can use it.

Best Regards

mhaley78 said:

Hi I'm having same issue could you let me know where the relay is that needed changing please

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