I'm off to look at a 325i. The guy selling it said he got the car as a result of a dead ecu. He does Auto Electrics & Diagnostics for a living and so fixed it.
The car looks clean etc and mechanics wise I know what I'm looking for, just have no idea about electrics.
Any ideas? pointers? sorry if this sounds a little dumb!
what would damage an ecu?
Moderator: martauto
an ecu can be damaged by anything,
water, putting the battery leads the wrong way on a jump start.
Too much to list, could just be the case of an alarm stopping the car from starting and the guy just said ecu to make it sound simple.
Not a big deal.
Start the car from cold, let it idle, try and turn it on and off a couple of times to test the immobiliser to see if there's any intermittent faults.
water, putting the battery leads the wrong way on a jump start.
Too much to list, could just be the case of an alarm stopping the car from starting and the guy just said ecu to make it sound simple.
Not a big deal.
Start the car from cold, let it idle, try and turn it on and off a couple of times to test the immobiliser to see if there's any intermittent faults.
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Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
If the average spanner monkey can't work out why a car won't start, then the last resort is to blame the engine ECU. In practice they are extremely robust, but they are complex electronic assemblies, and can fail for no apparent reason, as well as those listed above.
One good way of killing an ECU is to disconnect a spark plug lead with the engine running. This can result in the ignition coil flashing over from the king terminal to the - terminal, either externally or internally, and sending around 50,000 volts back into the ECU.
Of the few faulty engine ECUs I've come across, none have been faulty in such a way as to stop the engine running.
One good way of killing an ECU is to disconnect a spark plug lead with the engine running. This can result in the ignition coil flashing over from the king terminal to the - terminal, either externally or internally, and sending around 50,000 volts back into the ECU.
Of the few faulty engine ECUs I've come across, none have been faulty in such a way as to stop the engine running.
well said, i agreeBrianmoooore wrote:If the average spanner monkey can't work out why a car won't start, then the last resort is to blame the engine ECU. In practice they are extremely robust, but they are complex electronic assemblies, and can fail for no apparent reason, as well as those listed above.
One good way of killing an ECU is to disconnect a spark plug lead with the engine running. This can result in the ignition coil flashing over from the king terminal to the - terminal, either externally or internally, and sending around 50,000 volts back into the ECU.
Of the few faulty engine ECUs I've come across, none have been faulty in such a way as to stop the engine running.
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e30topless
- E30 Zone Team Member
- Posts: 13598
- Joined: Wed Aug 23, 2006 11:00 pm
- Location: surrounded by scrap
IMO the only thing that can damage an E30 ECU is age, or some knob wrongly fitting a useless generic chip,
is the 325i pre 88 ? the early 2 row ecu regularly suffers from dry joints,
as for disconnecting a spark plug lead with the engine running thats shocking !!
is the 325i pre 88 ? the early 2 row ecu regularly suffers from dry joints,
as for disconnecting a spark plug lead with the engine running thats shocking !!