Nice one bgsats, let us know which relay / connections it was, I can't think of anyone else having this problem so it would be good to keep it on record.
See if you can take a picture of where the problem was, or describe location or the terminal numbers or something?
Cheers.
HDI won't start - off road 5 weeks - help please!!!
Moderator: Moderators
Standing in front of the car with the bonnet open remove the large black plastic cover on the left. (Maybe there should be some clips, nothing on mine.) On top of the ECU unit (maybe 5 inches wide) is a black multiplug type connector about the same width as the ECU. Lift the metal clip securing the connector, the connector can then be removed. The pins are numbered on the ECU but not on the connector, so it may pay to slide out the ECU and draw a diagram to have under the bonnet while you check voltages.
My ECU was a Bosch o 281 001 978 - other Bosch units may or may not give similar readings.
Pins 33,49,51 and 53 should all be grounded, so check for continuity between these and battery negative. Pins 1, 29 and 69 should be 0v. with ignition off, battery voltage with ignition on. I was told a missing live on one of these pins was a likely cause of the problem - 2 were dead on mine! If only 1 is dead, it was suggested I borrow a live feed from one which was working. Pin 86 should be battery volts with ignition off, 0v. with ignition on. Pin 87 should be 0v. with ignition off, o-1v. for 2 secs when ignition is switched on, then battery voltage.
As I had several incorrect readings, it was suggested the relay next to the ECU could be faulty. This is the only other electrical item in the black plastic box holding the ECU. The connector can be removed by pulling out (sideways) the metal clip, using a screwdriver. The pins are numbered on the connector. Pins 3,8,11 and 15 should be permanent battery voltage (I got correct readings there!) When the relay is activated, I was told pins 1,2,5 and 9 should be live out from the relay. There must be some discrepancy there, as position 5 in the connector has no pin at all! The theory was to test for a relay fault by replacing it with copper link wires. I linked the permanently live pins to 1,2 and 9 and the engine fired once but no more. However, on removing the links and replacing the relay, the engine ran normally, and has started every time since. I can only presume that by pushing copper wires into the connector I have removed some corrosion from the relay connector. Information courtesy of Chris at TotalTuning, Pontypridd.
My ECU was a Bosch o 281 001 978 - other Bosch units may or may not give similar readings.
Pins 33,49,51 and 53 should all be grounded, so check for continuity between these and battery negative. Pins 1, 29 and 69 should be 0v. with ignition off, battery voltage with ignition on. I was told a missing live on one of these pins was a likely cause of the problem - 2 were dead on mine! If only 1 is dead, it was suggested I borrow a live feed from one which was working. Pin 86 should be battery volts with ignition off, 0v. with ignition on. Pin 87 should be 0v. with ignition off, o-1v. for 2 secs when ignition is switched on, then battery voltage.
As I had several incorrect readings, it was suggested the relay next to the ECU could be faulty. This is the only other electrical item in the black plastic box holding the ECU. The connector can be removed by pulling out (sideways) the metal clip, using a screwdriver. The pins are numbered on the connector. Pins 3,8,11 and 15 should be permanent battery voltage (I got correct readings there!) When the relay is activated, I was told pins 1,2,5 and 9 should be live out from the relay. There must be some discrepancy there, as position 5 in the connector has no pin at all! The theory was to test for a relay fault by replacing it with copper link wires. I linked the permanently live pins to 1,2 and 9 and the engine fired once but no more. However, on removing the links and replacing the relay, the engine ran normally, and has started every time since. I can only presume that by pushing copper wires into the connector I have removed some corrosion from the relay connector. Information courtesy of Chris at TotalTuning, Pontypridd.
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Welly
- The moderator formally known as Welton
- Posts: 15033
- Joined: Tue Jan 10, 2006 12:52 pm
- Location: East Midlandfordshire
That, is incredible.
Did I not say that it would be something simple before, but it will be hard to find, and hey presto you did.
Good on ya fella you did good, I bet your very pleased to have it running again, I don't much like messing about with multi pins and relays but I suppose at your stage you would be willing to mess about with anything to get it working.
I always thought that the engine bay was a crap place to put a Computer, it's normally in the cabin around the passenger footwell, mind you thinking about it 406's can let in water here
Glad you got it sorted and thank you for your input, most interesting.
Welly.
Did I not say that it would be something simple before, but it will be hard to find, and hey presto you did.
Good on ya fella you did good, I bet your very pleased to have it running again, I don't much like messing about with multi pins and relays but I suppose at your stage you would be willing to mess about with anything to get it working.
I always thought that the engine bay was a crap place to put a Computer, it's normally in the cabin around the passenger footwell, mind you thinking about it 406's can let in water here
Glad you got it sorted and thank you for your input, most interesting.
Welly.
Cars in my care:
2021 Kia Spottage 1.6 Pez Turbo Dual Clutch Gearbox Trickery
2013 Renner Twingo - donkey work
2021 Kia Spottage 1.6 Pez Turbo Dual Clutch Gearbox Trickery
2013 Renner Twingo - donkey work