TC Lockup problem & Injection Pump Rebuild (related?) (1 Viewer)

[lumpy70]

Truck is a 1993 HDJ81 with an electronic A442F.

Here's the breakdown:
I had my injection pump rebuilt by a reputable shop and re&re'd by my normal guy (I just don't have the time to pull this otherwise I'd do it myself).

Since the rebuild (which went well) my torque converter lockup, which is controlled by the O/D button on my shifter, won't engage. The O/D light flashes, but due to a series of miscommunication the shop pulled the light bulb so I couldn't 'read' the code.

Thinking it was the solenoid, I replaced that, then thinking it was the ECT (I found a cheap one) I replaced that, and still no love.

So I'm wondering if there is a mechanical or electrical connection that got either missed or mis-installed on the injection pump that directly affects the O/D and the lockup of the torque converter.

I've attached the diagram from the IP that says "Governor Assy, Torque Control" which is where my brain is leading...but I poked around last night and everything looks good.

Anyone got any ideas?

 

[Malleus]

Stupid question: why not put a bulb in and read the code?

Aside from that, I do not have your FSM, but, my '94 FSM (for the A442F), Drivetrain, Automatic Transmission, Troubleshooting section says

This troubleshooting section runs 41 pages, and 1.3 Mb (pdf); the EWDs, ECT (91kb) and Shift Lock (21 kb) are 8 and 2 pages resp. Suggest you start there.

You may be able to get the FSM from TIS, $15US for 48 hours. I have the xmsn section with me (obviously); PM me and I'll shoot a copy to you.

 

[lumpy70]

Not a stupid question, I just haven't gotten time to pull it all apart and put in the bulb.

It's on the list for this weekend.

I've got the FSM, thanks!

 

[Sarmajor]

The only component on the injector pump that looks able to throw a code related to the transmission is the throttle position sensor #22751. Code 41.
The OD button does not control torque converter lockup. The OD button disables 4th gear in the transmission. Lock up will still occur but only in 3rd gear which is as high as the transmission will shift to with the OD off.

I would be suspicious of the throttle position switch as one of the conditions to unlock or prevent lock is the TPS being at idle position.

 

[lumpy70]

So the consensus was correct, Error Code 41: Throttle Position Sensor...digging into that today.

I'm hoping it was just not connected but it's hard to tell, that wire disappears on the engine side of the injection pump.

 

[lumpy70]

Tested the TPS and it ohms out ok. Not sure if that 100% means it's working. Does it sit on top of something adjustable?

The only other things could be the harness (seems ok in engine bay and in dash), cluster? (but I think the cluster is dumb), or the ECM itself. Already replaced the ECT.

Maybe at $60 replacing the TPS is a good start.

 

[lumpy70]

Tested the TPS and it ohms out ok. Not sure if that 100% means it's working. Does it sit on top of something adjustable?

The only other things could be the harness (seems ok in engine bay and in dash), cluster? (but I think the cluster is dumb), or the ECM itself. Already replaced the ECT.

Maybe at $60 replacing the TPS is a good start.