Hi all, need some help if possible. I have a 2011 punto evo 1.4 with what I think is a wiring fault somewhere and just wondered if anyone else had had the same issue. Problem I have got is no cranking and imobaliser lock light staying on and no eml light at all. I have replaced the ecu kit from a doner car to rule out the key but the problem is still there. I also can only connect to the airbag ecu with multiscan and it has no dtc's present. Engine ecu will not connect, I have checked fuses and I can't find anything blown so I'm at a bit of a loss with it. Any help would be very much appreciated.
Technical Wiring problems?
- Thread starter Jay71
- Start date
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Technical Wiring problems?
Earth cable.. ??
Battery to chassis and gearbox
A fairly common failure
Battery to chassis and gearbox
A fairly common failure
Last edited:
Hi, sorry for the late reply been working away. I have put a jump lead from the engine block to the battery earth and problem is still there. I'm at a bit of a loss with it at the min
Right let’s start at the beginning it will be nothing to do with the ECU. When I check compression I unplug the ECU and the car turns over fine
What tools do you have I guess a multi meter
Manual or automatic. Makes a difference
No engine check light would point to a voltage missing
Relay or Fuse possibly let’s see if I can find the wiring diagrams and places to test
What tools do you have I guess a multi meter
Manual or automatic. Makes a difference
No engine check light would point to a voltage missing
Relay or Fuse possibly let’s see if I can find the wiring diagrams and places to test
Hopefully someone could post a wiring diagram
Here’s the grande punto not sure how close they are
Body Computer M1 - connector G - is supplied directly from the battery from a line protected by maxifuse F2 of engine compartment control unit B1. It is ignition-operated (INT) at pin 32 of connector D. Pin 10 of connector H of M1 supplies a reference earth to the Body Computer.Power distribution to the vehicle (INT "ignition-operated, INT/A, "AVV", etc) is managed by the Body Computer that is connected to ignition switch H1:- ignition switch H1 is supplied by the Body Computer from pin 48 of connector D of M1 via a line protected by fuse F85;- ignition switch H1 sends ignition-operated signal “15/54” to Body Computer M1 at pin 32 of connector D;When the ignition key H1 is turned to its furthest position (START) - pin 50 - power is sent to the electromagnetic winding - pin 50 - if starter motor A20 - in accordance with the control strategy described previously:- ignition switch H1 sends a START signal to Body Computer M1 at pin 31 of connector D; and this in turn sends an enablement request to engine control unit M10 via the CAN network;- start-up takes place only in the presence of an enablement signal - from pin 62 of connector A of engine control unit M10: this engergizes the start-up enablement relay T18, located in engine compartment junction unit B1: the relay - supplied by an ignition-operated supply from a line protected by fuse F35 and relay T6 of B1: this ignition-operated supply (INT) is controlled from pin 1 of connector A of M1;- the start-up enablement relay T18 of B1 then sends a power supply to pin 50 of starter motor A20.Pin 30 of A20 - connector A - i.e. the actual motor, receives a power supply with the voltage coming directly from the battery A1.The direct current generated by alternator A10 (pin B+) - connector B - is sent to battery A1 via the MAXIFUSE box on the battery, passing through motor A20.
Here’s the grande punto not sure how close they are
Body Computer M1 - connector G - is supplied directly from the battery from a line protected by maxifuse F2 of engine compartment control unit B1. It is ignition-operated (INT) at pin 32 of connector D. Pin 10 of connector H of M1 supplies a reference earth to the Body Computer.Power distribution to the vehicle (INT "ignition-operated, INT/A, "AVV", etc) is managed by the Body Computer that is connected to ignition switch H1:- ignition switch H1 is supplied by the Body Computer from pin 48 of connector D of M1 via a line protected by fuse F85;- ignition switch H1 sends ignition-operated signal “15/54” to Body Computer M1 at pin 32 of connector D;When the ignition key H1 is turned to its furthest position (START) - pin 50 - power is sent to the electromagnetic winding - pin 50 - if starter motor A20 - in accordance with the control strategy described previously:- ignition switch H1 sends a START signal to Body Computer M1 at pin 31 of connector D; and this in turn sends an enablement request to engine control unit M10 via the CAN network;- start-up takes place only in the presence of an enablement signal - from pin 62 of connector A of engine control unit M10: this engergizes the start-up enablement relay T18, located in engine compartment junction unit B1: the relay - supplied by an ignition-operated supply from a line protected by fuse F35 and relay T6 of B1: this ignition-operated supply (INT) is controlled from pin 1 of connector A of M1;- the start-up enablement relay T18 of B1 then sends a power supply to pin 50 of starter motor A20.Pin 30 of A20 - connector A - i.e. the actual motor, receives a power supply with the voltage coming directly from the battery A1.The direct current generated by alternator A10 (pin B+) - connector B - is sent to battery A1 via the MAXIFUSE box on the battery, passing through motor A20.
Thanks for all the replys and help guys. So I have eventually fixed it, turned out to be a broken wire on the yaw sensor plug by the hand brake. There a 6 wires that go into the yaw sensor and my brown one had broke. Its a bit of a bad design as the sensor is positioned facing the handbrake, so when it is being operated up and down the bottom of the handbrake cover under the centre consul catches the wires so over time I suspect that is what cause my wire to fail. I hope that made sense and can help someone else in the future. Thanks again for all your replys 
