[Cj987]

I am at such a loss any help, diagrams or advice would be great!
My 2011 Jeep Grand Cherokee threw a p0743 code a few weeks ago while driving, it went into limp mode. It had no other signs other than a sudden engine light and limp mode. No clunking, shifting issues or anything prior or even at the time the engine light appeared.

After testing the TCC solenoid it did have a low resistance. I replaced it as well as the Transmission Conductor Plate for good measure. I flushed the fluid and ensured it was at the proper level.

Hooked the battery back up, Turned the vehicle on, still popped a code. I cleared the code with a cheap scanner. I drove it, it was still in limp mode and the code popped up immediately in pending.

I checked all the wiring. Everything seemed fine. No burnt, exposed or loose wires anywhere. I’m at a total loss.

 

[ColdCase]

The 2011 V6 has a NAG transmission. p0743 is a connection issue to the torque converter clutch solenoid, the PCM doesn't like what its seeing.

The NAG has a tendency to leak fluid around its electrical connector leading to poor connection. Dunno if thats your case, but there are several discussions around on how to repair/replace. If no one jumps in here, I'll try to take a look when I get back.

The PCM has a tendency to develop corrosion in its connectors, you may want to inspect those pins.

 

[Cj987]

I haven’t found any leaks and the pcm is super clean.

 

[TenchFries]

Edited, duplicate of top Post!


Hi all. I have a conundrum. Driving home from work the other day, my 2011 3.6l threw an engine light, slammed out of overdrive, into what I presume is 2nd or 3rd, and forced me to limp home.
Upon investigation, I found only 1 code. P0743, TCC circuit fault.

After some research, I check the TCM pins and Trans plug and found 4.5ohms to the TCC solenoid. So hoping for the best I drained the W5a580/NAG1 and replaced the TCC solenoid, Conductor Plate, Filter. Fluid and gasket.

Filled her up, checked level with a custom made dipstick and used the dash readout for trans Temps. Engine light remained.

Disconnected battery to force a reset, code returned. Cleared all codes with scanner, code went pending then returned.

Went for a drive. No shift, No new codes. Just my archenemy. P0743.

I have visually checked as much of the harness as I can, No visible breakage. I have tested continuity between TCM plugs and Trans plug. Just fine.

All ABS/Wheel speed sensors are on good shape.

Resistance on old TCC I'd actually perfect, at 2.5 ohms in my hand.

What the heck am I missing here???

Sorry for the blog post, but I'm at my last legs for solving this. Any insight is appreciated.

What bothers Me the most is none of p0743 symptoms are present. No awkward lockup, slippage, nothing. No shift at all.

Does TCM need cleared/reflashed/replaced?

Is trans toast?

Is it the harness?

SOS send help!

 

[Nejeep]

I haven’t found any leaks and the pcm is super clean.

My 2006 GC had the NAG1 transmission and it had a leak inside the electrical connector. You may not see it leaking externally but the ATF can get inside the connector and pins causing issues. The only way to find out is to remove the connector and inspect it.

 

[Cj987]

My 2006 GC had the NAG1 transmission and it had a leak inside the electrical connector. You may not see it leaking externally but the ATF can get inside the connector and pins causing issues. The only way to find out is to remove the connector and inspect it.

I’ve already unplugged them all and they were clean. I cleaned them again for good measure.

 

[Ozzz613]

Hi im in the same situation, tested from tcm side, all solonoids ohm out in proper spec. Pin 17 & 38 on tcm side is 3.1ohm.

Did you find a solution?

 

[ColdCase]

Additional info:

 

[Cj987]

To everyone with the same issue, sudden LIMP mode, one strange code, replaced all parts but no fix.
It was my TCM. Replaced it and had a friend flash it to the vin #. Instantly fixed, no codes as if it never happened.
Good luck!!

 

[Cj987]

Hi im in the same situation, tested from tcm side, all solonoids ohm out in proper spec. Pin 17 & 38 on tcm side is 3.1ohm.

Did you find a solution?

It was the Tcm.