2003 Nissan Sentra 2.5 LE Engine QR25DE


Asked by Oct 07, 2014 at 04:54 PM about the 2003 Nissan Sentra 2.5 LE

Question type: Maintenance & Repair

Can you test ECM when car is not running?  How do you disconnect ECM from wire harness?

5 Answers


Yes it can be checked,not running,and why would you want to take it out,unless you are replacing it?


If we need to replace it, we want to do it ourselves, not pay a garage. How do you test it?


It will need scanning,


You will need to go to the shop anyway, unless you know what you're doing. Maybe we can help you here if we know what problem you're trying to solve.

1 out of 1 people think this is helpful.

About a month ago the service engine light came on for a couple of days and then went off. We put it on the hand held coder and it read # 4 cylinder. we replaced the spark plug and it went off again for a couple of days. Then back on again. We changed the coil pack and it went off again and then back on. Still reading #4 cylinder on coder. then we seen antifreeze in the oil so stopped driving it and started to tare it down to replace head gasket. When we had it all back together it wouldn't start. we have put on a new cam and crack sensor. We have check the wire harness. The 3 wires running from the ECM to the coil packs. they are not broken. Got one new coil to see if there would be any spark there but there was no spark. When you try to start it the 1st and 2nd time, it will spark a little bit on 2 and 4 cylinder and after that nothing. so we thought the next step would be the ECM.

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