meyer30

iTrader: (2)

I'm having some serious issues with my T/A. I've been told to check the grounds to the ecm. I'm checking them with an Ohm meter, but I'm getting different readings, and want to make sure I'm checking them right. On the ecm ground I connect the red lead and put the black lead on a body ground, with the ignition on I get -1.1 with the ignition off I get -0.1. Then I checked the map ground and one other I get no reading at all. I'm checking these from the actual connections at the ecm while there unplugged. Am I doing this right? What should I be looking for? Thanks for the help

Fullsizewagon

Different readings with ign on & off is due to a small voltage induced in the grounding due to the currents consumed. Test with nothing on at all, not even interior lights, in fact just disconnect battery negative to be sure. Some sensors, like the map & tps, are not grounded to the block itself and the ground just goes straight from the ecm and to that sensor. Others, like the O2 sensor, are grounded to the block and relies on a (number of) ground wire(s). All this would be apparent on a decent wiring diagram.

meyer30

iTrader: (2)

Ok so when I'm testing it shoud I be using ohm or volts? And what type of reading should I get if it's a bad ground?

meyer30

iTrader: (2)

Well I checked the grounds thru the ecm and they all checked out fine.

Fullsizewagon

You test it with Ohms (since you will want to test w/o battery), and with the ecm disconnected (because it connects all the grounds together internally). You should get readings between 0.1 and 0.3 Ohms.
If you're still at a loss of where the fault is, feel free to share the symptoms with us.

meyer30

iTrader: (2)

Well since it started I've replaced the entire dist and coil. Second time I've replaced the ignition module. I start and drive the car fine for about 5 min. Once I've gotten into it a couple of times the ses light comes on real quick and the car shuts down and as soon as it shuts down it starts running again. No stored codes. Once I get into my neighborhood it starts to idle like garbage and just dies. It'll run in park but not in gear. I'll let it sit for a while and then it happens all over again. If I let it die when I come to a stop I get a code 33 and 42.