Possible bad ecu?

[bronzite30]

1987 325i convertible. Bosch motronic 1.3
So while trying to figure out my no crank issue, I noticed the fuel pump wasn't turning on. I checks for voltages and noticed that the control side of the fuel pump relay wasn't grounding through the ecu. the main relay control circuit is grounding through the ecu and operated correctly. the ecu should ground the relay at KOEO, but doesn't, is this leading to a bad ecu or is there another way to fix this without having to find an Ecu?


Thanks

[bronzite30]

Bump

[325e87]

Don't forget to check wiring to the ecu. Also swap relays, just to be sure.

[bronzite30]

Don't forget to check wiring to the ecu. Also swap relays, just to be sure.

That's a exactly what I did, it gets 12 volts all the way to pin 3 of the ecu, but does not ground it to turn the pump on

[bronzite30]

Bump

[Gregs///M]

There is a section in the Bentley manual that is specific to testing the DME. Run through each pin and test the logic. You can do it all with a multimeter.

Basically, test and verify that all your IO is working before swapping the DME. However, you can buy a DME around $60-$80 so swapping it might be less time consuming.