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ECM, starter motor connector

Featured Replies

99 Legacy Outback..........

 

 

Throwing check engine light code P1100, Starter Switch Circuit Low Imput

 

was advised If the starter operates (which it does), there is an open, or ground short circuit between the ecm. and the starter motor connector. How do I trouble shoot this??

 

Car has stalled recently a couple of times at traffic lights. Suspect the problem involving the ecm is responsible for this. Car restarts easily after a stall. I need to fix this, before it gets worse.

 

Any advise greatly appreciated. Thanx

Edited by Rooster2

Start signal circuit will not cause the engine to stall. That circuit only provides a signal to the ECU that the key has been turned to the start position. What exactly the ECU does with that signal I'm not sure of.

 

The code is p1100, not p0100?

  • Author

Battery cables tight?

 

O.

Will check that out............Thanx

Rooster2, on 22 Oct 2016 - 13:22, said:

99 Legacy Outback..........

 

 

Throwing check engine light code P1100, Starter Switch Circuit Low Imput

 

was advised If the starter operates (which it does), there is an open, or ground short circuit between the ecm. and the starter motor connector. How do I trouble shoot this??

 

Car has stalled recently a couple of times at traffic lights. Suspect the problem involving the ecm is responsible for this. Car restarts easily after a stall. I need to fix this, before it gets worse.

 

Any advise greatly appreciated. Thanx

 

It won`t be a ground short.The starter would not work.

 

Check for opens/high resistances by unplugging thr ecu and putting your ohmmeter  between the appropiate pin and the starter

motor connector.

 

Better yet,leave it plugged in and backprobe the connector w/a voltmeter.

Pull the fuel pump fuse or relay.

Note the voltage w/starter cranking.

 

The ECU uses this signal to furthur enrich the mixture for starting.

 

I have not seen it and I don`t follow the logic,but,apparently sometimes the ECU becomes confused when it does not see the start signal which causes subsequent running problems

 

Something to think about.

Edited by naru

  • Author

It won`t be a ground short.The starter would not work.

 

Check for opens/high resistances by unplugging thr ecu and putting your ohmmeter  between the appropiate pin and the starter

motor connector.

 

Better yet,leave it plugged in and backprobe the connector w/a voltmeter.

Pull the fuel pump fuse or relay.

Note the voltage w/starter cranking.

 

The ECU uses this signal to furthur enrich the mixture for starting.

 

I have not seen it and I don`t follow the logic,but,apparently sometimes the ECU becomes confused when it does not see the start signal which causes subsequent running problems

 

Something to think about.

 

If I do find a voltage drop, what is the solution to fix the problem??

Edited by Rooster2

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