Shoot, found a PCM with only 117k on it in AZ but it’s from a 2 wheel drive.

Looks like the code scanner is choosing ISO 9141-2 when linking (edited, had it wrong the first time).

Funny enough it also says the VIN is blank when I go into vehicle info, other vehicles I’ve had plugged in so list the VIN.

 

Actually, I don't think 2 or 4 wheel drive matters at all. The PCM has no way of knowing how many drive wheels you have, nor does it have any idea of how many of them you are using......

 

Thats what I was thinking, isn’t the 4wd light in the cluster triggered by the transfer case and not the pcm? When looking at reman computers, there’s two different part numbers for a 5.9 with federal emissions, I was assuming that meant ac or no ac thinking the compressor clutch engagement is commanded by the pcm.

 

It does get a signal when 4wd is engaged and it affects the ABS though.

 

Federal emissions dictates how many O2 sensors you have

 

I haven't seen anything in the wiring diagrams that tell the PCM the truck is in 4wd. If it has 4 wheel abs, THAT I could see getting clued in..... but, so far as I know, it doesn't care either...... Of course, I am more familiar with the 98 (early) and older trucks.... an 01 *might* care more.....

 

That is a good point, not possible to stop a single wheel from locking up when both axles are being driven at the same time in 4wd. I do know this truck is rear wheel abs only, it doesn’t have the 4 wheel abs option.

The junk yard selling is offering a 6 month warranty and is saying it will work, so I suppose go for it and see what happens. I really prefer this one with 117k vs all of the 170-220k mile ones I’ve been able to find.

 

Gotta love mid generation changes

 

I always like to gamble once and a while I say go for it

 

According to the service manual, this truck is equipped with CCD for the computer protocol. Also, here is what it lists for PCM inputs, looks like AC would be the main difference from truck to truck besides the different trans inputs on an automatic:
NOTE: PCM Inputs:
• A/C request (if equipped with factory A/C)
• A/C select (if equipped with factory A/C)
• Auto shutdown (ASD) sense
• Battery temperature
• Battery voltage
• Brake switch
• CCD bus (+) circuits
• CCD bus (-) circuits
• Camshaft position sensor signal
• Crankshaft position sensor
• Data link connection for DRB scan tool
• Engine coolant temperature sensor
• Fuel level
• Generator (battery voltage) output
• Ignition circuit sense (ignition switch in on/off/ crank/run position)
• Intake manifold air temperature sensor
• Leak detection pump (switch) sense (if equipped)
• Manifold absolute pressure (MAP) sensor
• Oil pressure
• Output shaft speed sensor
• Overdrive/override switch
• Oxygen sensors
• Park/neutral switch (auto. trans. only)
• Power ground
• Sensor return
• Signal ground
• Speed control multiplexed single wire input
• Throttle position sensor
• Transmission governor pressure sensor
• Transmission temperature sensor
• Vehicle speed inputs from ABS or RWAL system