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How to use GM Tech 2??

Big T

Big T

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Plugged it in and lost as to how to use it.

1. Would like to set TDCO. (Priority 1 today).

2. Would like to pull ABS Codes. (Priority 2 down the road)

3. Would like to pull Transfer Case Codes. (Priority 3 down the road).
 
Alright, played around with it and got these results without trying to set TDCO. Still looking for how to do that.
 

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I have a custom bent box wrench for the IP nuts. Do I have to pull the T-stat housing from the crossover to get to the bottom nuts?
 
ak diesel driver said:
If you haven't initiated a relearn it's just showing the old number the pcm has stored.
Click to expand...

And how do I initiate a relearn?

I have leak on one of the injector lines at the pump. Same thing happened the last time I pulled and reinstalled them. They're a pain.

I runs somewhat rough. I got a P0266 code on the Tech 2, saying a cylinder 2 imbalance. Wondering that is related to the leak, because that is the line I was having trouble with.
 

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I believe there should be a section for tests, and its under there. It's been over 5 years since I did one, so I just don't remember. I've been wanting to get one of these just to have. They're so friggen cheap from china now, and it would give me another toy to play with. It's just too bad GM pretty well obsoleted them as of the 2012 MY.
 
Only procedure I could find about it.

In order to initiate the relearn:

1. Hook up your scan tool.
2. Start the engine and idle engine until coolant temperature is at least 170 degrees F.
3. Clear any diagnostic trouble codes, if any. Then turn the engine off.
4. Turn the ignition switch to the “On” position. Do not start the engine.
5. Prepare the PCM to activate the offset relearn by placing and holding the accelerator pedal in the fully open position for no less than 45 seconds. Then release the pedal.
6. Turn the ignition switch to the “Off” position for 30 seconds. To confirm that the PCM has powered down, you should get a “No communication with vehicle” message on your scan tool.
7. Now start the engine and make sure that the coolant temperature is 170 degrees F or higher.
8. As soon as the engine coolant has reached 170 degrees F. and the engine speed is below 1500 RPM, the PCM will automatically learn the new TDC offset. A slight stumble in engine RPM is indicative that the new TDC has been activated.
9. Verify the TDC offset reading on your scan tool. The TDC offset should be between -0.25 and –0.75 degrees. If the TDC offset is within the specification, the relearn is completed. If the offset is out of specification then the injection pump must be adjusted.
 

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WarWagon said:
Only procedure I could find about it.

In order to initiate the relearn:

1. Hook up your scan tool.
2. Start the engine and idle engine until coolant temperature is at least 170 degrees F.
3. Clear any diagnostic trouble codes, if any. Then turn the engine off.
4. Turn the ignition switch to the “On” position. Do not start the engine.
5. Prepare the PCM to activate the offset relearn by placing and holding the accelerator pedal in the fully open position for no less than 45 seconds. Then release the pedal.
6. Turn the ignition switch to the “Off” position for 30 seconds. To confirm that the PCM has powered down, you should get a “No communication with vehicle” message on your scan tool.
7. Now start the engine and make sure that the coolant temperature is 170 degrees F or higher.
8. As soon as the engine coolant has reached 170 degrees F. and the engine speed is below 1500 RPM, the PCM will automatically learn the new TDC offset. A slight stumble in engine RPM is indicative that the new TDC has been activated.
9. Verify the TDC offset reading on your scan tool. The TDC offset should be between -0.25 and –0.75 degrees. If the TDC offset is within the specification, the relearn is completed. If the offset is out of specification then the injection pump must be adjusted.
Click to expand...
This is the manual procedure which works for most OBD2 trucks, but not all. You still need a scanner to see what the learned value is.
 
Found my fuel leak. I had detached the injector line at #2 injector to facilitate attaching the line at the IP and forget to put that nut back on the injector, thus the error code for imbalance at Cylinder #2.

Got it running, but it's throwing code P0335 - Crank Position Sensor Circuit A. Attempt to clear and it comes back. Have not done the relearn procedure. Engine is running much smoother than before.
 
Cleared code. Did the relearn. Starts right up and code did not return. Also idling at normal rpm, whereas is it was faster before. Going to hook up GM Tech 2 to see what's up.
 
I think I need to download the CD that came with the Tech 2 into a laptop and then download it into the Tech 2. That should get me ABS and Transfer case stuff.
 
Well 2 hours after a 4 mile trip to and from the supermarket, I went to start the truck and it would not light. Turned over fine, but it was as if it was getting no fuel. Tech 2 showed no codes. No time to trouble shoot. Working in SF for the week. Revisit it on Friday.
 
Thinking about this, I will try the spare PMD on the truck. The reman IP came with a new PMD on the side. I was wishing that I had a worthless old PMD to swap onto it, leaving me the new one to use as a spare. Actually, we do have an old one on the IP of the engine we took out of the '95 wreck. How hard is it to swap them on the IP?
 
Just get a heatsink and good extension cable for the "spare PMD". The little screws will wind up in the engine valley... And this doesn't solve the known random problem of mis-machined or damaged PMD mounting surface that could be causing a NEW PMD to overheat to ruin/failure. Do they have paint seals on the PMD screws for warranty purposes?

Not sure why you don't have a bumper mount PMD on this rig yet. :confused: Admittedly I ran our 1995 for a while on the pump mount and wasted money on a new bumper mount chasing what turned out to be the dammed kinked hose behind the FFM. May not have been a waste as I never did have PMD problems including testing an experimental PMD. Cold weather I hear killed the experimental units.

Buried in here is a PDF electrical troubleshooting guide (DS4 Cal resistors) to make sure the PMD is working aka with voltmeter etc. so you can verify the problem. I didn't say fun. :wtf: http://www.thetruckstop.us/forum/th...-5-db2-5-7l-info-online-from-stanadyne.26581/

If this was mine I would go external PMD with a made in USA extension harness @Burning oil and then troubleshoot further if needed. I would write off the PMD on the pump and mounting surface for the heat sink till it proves it's innocence. Being frugal one could run the tests and make them warranty a PMD. Balance that with the PIA of doing the trons tests when it breaks down, PIA of warranty, and if they want the entire pump back for a PMD...

The above ASSUMES a PMD issue. if you don't want to assume you have to run the electrical tests as something else can be wrong. For instance a worn head and rotor giving you the classic no hot start...
 
I have a bumper mounted PMD and that is what it's running on. Or was running on. See my signature line for the '99. I believe that PMD has been there working for like 9 years now.

My son has a spare PMD that I can plug in for testing. Have done this previously.

This was not a hot start attempt. 2 hours after a 4 mile run.

I want the new PMD off the reman pump for a spare, but the screws do have paint seals on them, presumably for warranty.
 
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