How to check your ECM ground
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How to check your ECM ground
Apart from a bad battery one thing to suspect when odd codes get thrown is a bad ground somewhere.
It might help to know that the OBD port pin 5 goes to ground via the ECM while pin 4 is grounded directly.
Pin 16 is battery volts so you should see the same voltage between 4 + 16 as 5 +16, and the resistance between 4 +5 should be a fraction of an ohm.
It might help to know that the OBD port pin 5 goes to ground via the ECM while pin 4 is grounded directly.
Pin 16 is battery volts so you should see the same voltage between 4 + 16 as 5 +16, and the resistance between 4 +5 should be a fraction of an ohm.
Last edited by steveinfrance; Feb 23, 2013 at 06:18 AM.
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From: Limousin, France
Pins 4- 16 is also an easy way to measure battery voltage without pulling the boot liners apart.
Bear in mind your OBD reader gets its power from pin 12 so leaving it connected will flatten your battery.
Bear in mind your OBD reader gets its power from pin 12 so leaving it connected will flatten your battery.
Last edited by steveinfrance; May 23, 2013 at 03:40 AM.
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