Hey guys thanks for letting me join your cool site. A couple of days ago I purchased a 99 camaro v6 off a trading website. It supposedly had a bad pcm and body damage to the front end. Well I get it home after a couple hours with a uhual dolly. Lol I'm trying to diagnose it now to be sure it's the pcm. The starter does nothing the instrument cluster did at the milage and had usual check engine lights on now it quit also. The fuel pump doesn't come on. I thought the problem may have been the bcm so i switched it with a known good and matching resistance. I have also tried a spare ign switch. I have a 96 camaro and firebird that can be used for parts. If any of you guys have any ideas please share them! ! Thanks in advance:-)

 

Update found blown instrument cluster fuse replaced now have gauges back. Still no starter or fuel pump though:-(

 

Is the Starter Relay clicking when you turn the key to start? If not...Need to diagnose that first, Let me know.


Probably need to check all the fuses in the 2 underhood fuse boxes, The Starter fuse is in there somewhere, If blown the Relay will be dead.

 

Whatever you do, do not apply 12v to the output from the PCM that goes to the fuel pump relay or it will damage the PCM driver unless you unplug the pcm first.

Does the fuel gauge work? If so, that part of the pcm is ok.

 

with previous front damage check for a pinched wire, may have grounded when you were moving it and blew that fuse.

 

Guys thanks for your wisdom:-) so far the fuel guage appears inop. The gm scanner tool I rented says it cannot communicate with the pcm. And I have grounded tdr ground wire that goes from the bcm to the relay. I should have mentioned earlier ive pulled and checked/ replaced any fuses I find (drivers door and two underhood) quick question can a failed pcm kill the starter? ??

 

Also no clicking from Starter or relay sorry guys i forgot to mention this.

 

Use a multimeter to check for 12 volts dc at both ends of the PCM BAT and PCM IGN fuses referenced to chassis ground. One is in each of the underhood fuse boxes. The goal here is to see if voltage is present there, not to test the fuses; although that is done also. Have the ignition switch on while doing the check. If you don't have a multimeter, you can buy one from Harbor Freight for about $6.

The pcm can kill the starter and many other things. I suspect some bad/damaged wires after a collision, like Craby stated. A lot of mechanics see that the pcm isn't working, don't investigate farther, and think it is defective. Like anything, it can fail; but it is one of the hardiest parts in the car.

 

The PCM has nothing to do with the Starter relay circuits.


The control side of the Starter relay.....
When the Ignition switch is turned to "Start", 12 vdc is sent to the neutral safety switch (Through the Starter fuse), If the shifter is in Park/Neutral, 12 vdc is sent to the Starter Relay (Terminal 85).


If the BCM gets the correct resistance from the key, It will send a "Starter Enable" Ground to the Starter Relay (Terminal 86).