V1 Williamj95 Build

[Gtstorey]

That sounds a lot more like a starter/battery/relay/ground issue.

 

[ah.b.normal]

I don't know if your car has the coil around the ignition switch but I had a no start prob and if I held the coil tight to the switch body it will start. A zip tie holding that coil tight to the side of the switch cured the problem.

 

[williamj95]

I think I have traced down the cause of my problem. I put a volt meter on the wire that goes from the park/neutral position sensor on the transmission to the ECM. I'm getting 0 volts whether the trans is in park or reverse. I'm thinking there should be a signal on that wire when the trans is in park to tell the ECM it's safe to start the engine. Unfortunately, I short on cash right now and that sensor is $100. Hopefully I can get one next month. Once I've confirmed that is the issue I'll post an update.

 

[Gtstorey]

I think I have traced down the cause of my problem. I put a volt meter on the wire that goes from the park/neutral position sensor on the transmission to the ECM. I'm getting 0 volts whether the trans is in park or reverse. I'm thinking there should be a signal on that wire when the trans is in park to tell the ECM it's safe to start the engine. Unfortunately, I short on cash right now and that sensor is $100. Hopefully I can get one next month. Once I've confirmed that is the issue I'll post an update.

Are you trying to trouble shoot this without consulting a wiring diagram? That's next to impossible on modern vehicles. Your assumption may be correct, but I wouldn't bet a $100 on it. If you will add your donor to your signature, I'll post the diagram this evening. I know it, but I had to dig through your post to figure out what the donor is.

 

[Desert Sasqwatch]

Alternative: almost every boneyard has at least one automatic transmission Cobalt or HHR or Saturn or Malibu or other similar GM vehicle with a shifter. Get one or two from there - save a bunch of bucks to spend on something else.

 

[williamj95]

Gtstorey, I appreciate the help, but I have the diagram. That is what I used to help me trace this down.

 

[Gtstorey]

So have you grounded pin 12 on the p/n switch and see if it will start? You will not read voltage on that circuit when it is plugged in when in p/n since that circuit is grounded in that position. It uses that voltage being pulled low to know that it is safer to start.