MyE28.com

Posted: **Mar 22, 2006 10:23 PM**

My M5 would'nt start this afternoon. I had fuel and no spark. I switched out the ECU with my spare one that has a stock chip and it fired right up.

Cris

Posted: **Mar 22, 2006 10:27 PM**

Sometimes vibration will cause some of the soldered joints to crack, making poor connections.

Posted: **Mar 23, 2006 10:30 AM**

cj wrote:My M5 would'nt start this afternoon. I had fuel and no spark. I switched out the ECU with my spare one that has a stock chip and it fired right up.

Cris

Possibly a defective output transistor for the ignition side. I haven't seen recommendations for what type of transistor to use. I do know that you WILL NOT find a cross reference for the transistors used in the ECU. Maybe someone will chime in with a transistor PN that will work.

Rich

Posted: **Mar 31, 2006 11:43 PM**

The weirdness continues. I went ahead and mounted the ecu in place with the car off. I tried to start it once the ecu was mounted and nothing. Cranked but would'nt fire. Again no spark and I did'nt smell fuel. Since I had the other ecu handy, I unplugged the mounted one and plugged in the other ecu. It fired right up. Any insights?

Cris

Posted: **Apr 01, 2006 12:22 AM**

Broken wire in the harness to the ECU?

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What would cause an ECU to go bad?

What would cause an ECU to go bad?

Re: What would cause an ECU to go bad?