I e-mailed him the "No Response" test right out of the factory manual yesterday. It that 26 page long one with pics of all the pinouts and a flow chart. I bet he finds something soon. .

 

I would like to have a look at that. Please send that to me as well. PM me with your email address.

CM

 

Well I guess I should have kicked myself when I was getting the continuity reading at the cables. I had everything shut off that I could possibly think of, except the hood bulb was still plugged in. LOL Anyhow, I'll get on with what I found the problem to be. I never would have guessed it, except the harness part I suppose. Yesterday after I ripped the entire harness out from the engine compartment I went through it with a fine tooth comb. By that I mean I stripped it down to wires and a few pieces of tape placed to hold configuration in place. I found several minisquel issues that I took the time to repair, factory splices that dry rotted, a few plugs where the wire going in was rotted and, looking rough, etc etc etc..... Then as I was getting to the last of the sensor plugs for the oxy sensors and the likes I saw the problem big as anything. I had four wires of the TCC plug connecter bare about one inch coming out of the plug. I even read the manual and it stated that the TCC for the 4 speed automatics was linked directly to the PCM. I truly wish that had been mentioned in the troubleshoot flowchart in the Haynes manual I have been using!!!!!!!!!!! LOL Strike that one up for lesson learned.....LOL.... So after I reassembled the harness, got it back in my truck, and put the starter and alternator back in from getting them tested, I put the spark plug wires on, put the new PCM back min and fired it right up!!!! I feel like a dummy for the close to $700 I put in new parts, and the basically six days I spent trying to figure it when it was about a $3 problem that would have taken a couple hours max to fix. Oh well, I learned a valuable lesson on this adventure. Thanks for all the input, especially to you CM. I hope whoever reads this thread learns something for the next time they are having problems with a PCM not communicating. It may just save a bundle in your wallet. Everyone take care, this is an awesome site...

 

When it comes to flow diagrams and troubleshooting flow diagrams, it's tough to find good charts. The Haynes and Chilton books are fine for simple diagram layouts but, by no means is that going to go into enough detail to help sort out shorts such as this.

This is another one to add to the list of shorts that will cause the PCM to shut down in addition to the two 5-volt PCM version and to the one 5-volt and one-8-volt supply PCM version.

The TCC (3-speed and four speed) and OD Solenoid (4-speed only is off an entirely different pinout at the PCM than the 5 and 8 volt supplies. Now, whether it shares the same supply, I don't know. It may. I would need to see the PCM schematic in order to verify that but, either way, all we need to know is that this will also trigger the auto shutdown mode within the PCM to prevent catastrophic failure.


3 speed:
PIN 54 TCC solenoid

4 speed
PIN 54 TCC solenoid
PIN 55 OD soleniod

CM

 

TNtech,

I never received the E-mail you sent me with the no response test. I was looking for it but it never made it to me. Would it be possible for you to send it to me again. Thank you.

 

Is there any chance I can get a copy of your "No Response" test,also? I am having the exact same problems. Thanks in advance

 

Missouriboy1 hasnt logged in for 3 months dont think he is trolling around.

 

Ok, have followed the flow chart through to the point of ground sensor wire not lower then 1 volt, chasing the ground wire down. have gotten to pulling the ignitionm on ground rhat when I pull the ignition run fuse. My voltage drops from 1.7 to .4 will replace switch tomorrow. any other suggestions?

 

Sometimes "lower than 1 volt" means they are looking for O. Also below a certain Ohms may mean Infinity. Not an actual reading. As in "Is the resistance below 5 ohms?". Youre looking for a reading of 1 (which may be continuity with ground) or Infinity (or OL) depending on which circuit you're testing and the purpose of that particular step. Even with the test procedures in your hands, things may still not be totally clear. It takes practice and understanding which comes with experience.

 

OK, so new ignition switch installed, still have 1.6 volts on my ground sensor wire. Sorry if my last post was a little incomprehedable. Little tired, little tipsy. Thank you very much for your help TNtech. INVALUABLE, And greatly appreciated, cannot get even remotely as much assistance from the local dealer ship. Any way will keep chasing my ground wire for leaking voltage. Also looking for why my 12 volt primary supply is getting no voltage.