2011 KK Liberty - Cold Weather - not upshifting error TCM P0882

[kiwi_outdoors]

On our recent trip to Idaho towing a small camper, everything was fine, including crossing the Sierra Nevadas, until the 3rd morning. It was cooold – a bit above freezing. The ****** would not shift above 2nd gear. The temporary fix was to disconnect the battery – this fix lasted all day. Next day – same routine. And the day after. And the next day.

Then the overnight temperature dropped to around 27 deg F. Same problem, but the fix involved warming up the car, doing the battery disconnect, driving a bit, and then repeat the battery disconnect trick.

The code is P0882 Transmission Control Module Power Input Signal Low.

Has anyone on this forum had this problem, and if so, what was the fix?

(BTW - the problem occurred both with and without the trailer 7-pin wiring plugged in to the Jeep).

 

[LibertyTC]

If it is low on fluid not good.
Hopefully one of the KK members has more info re: P0882
See also this thread. https://www.jeepkj.com/threads/transmission-error-codes.61739/
2011 ok..No real dipstick - use ATF+4 fluid only.
Good info= See tool for reading fluid level: https://images.oreillyauto.com/parts/img/documents/mtm/917-327instr.pdf

 

[kiwi_outdoors]

If it is low on fluid not good.
Hopefully one of the KK members has more info re: P0882
See also this thread. https://www.jeepkj.com/threads/transmission-error-codes.61739/
2011 ok..No real dipstick - use ATF+4 fluid only.
Good info= See tool for reading fluid level: https://images.oreillyauto.com/parts/img/documents/mtm/917-327instr.pdf

The problem is electrical - not related to ****** fluid level. Else the battery disconnect trick would not have worked on those cold cold mornings.

Now back in warm California, the problem is not occurring (but still needs finding and fixing).

 

[kiwi_outdoors]

So we did another camping trip a week later - out to Utah and back, towing our camper. The problem occurred twice, only after the first start of the day, typically after sitting overnight leading to a cold morning. But not always very cold. The same fix worked in both cases. It sometimes sets the check engine light, but not always. Its always the same code, P0882.

 

[blackhawk]

As per dtc chart, it could be the transmission control relay. You can swap it and clean contacts.
It can also be a short to ground (see attachment)
You can also check the wiring (see attachment)

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[kiwi_outdoors]

well, I bought a cheap 2-channel FNIRSI 1013D oscilloscope from Amazon, I bought this solely to diagnose code P0882: low voltage between TIPM and PCM on my Jeep Liberty. Being able to see the request voltage and the output voltage on the same screen at the same time will be most enlightening.

Step 1 will be getting the two relevant wires exposed (from within their harnesses) and doing the scoping when the fault is not present, which is the normal case lately, now that we are back home in the sunny S.F. Bay Area..

 

[klc]

well, I bought a cheap 2-channel FNIRSI 1013D oscilloscope from Amazon, I bought this solely to diagnose code P0882: low voltage between TIPM and PCM on my Jeep Liberty. Being able to see the request voltage and the output voltage on the same screen at the same time will be most enlightening.

Step 1 will be getting the two relevant wires exposed (from within their harnesses) and doing the scoping when the fault is not present, which is the normal case lately, now that we are back home in the sunny S.F. Bay Area..

I’m so old I remember when o-scopes were expensive, and large. What’s the max frequency?

 

[KJowner]

I’m so old I remember when o-scopes were expensive, and large. What’s the max frequency?

And quality!

 

[kiwi_outdoors]

According to the Youtube reviews, its only good for about 30 MHz (not the claimed 100 MHz). Quality seems fine - there is not much to it, a case, a display, a mainboard, battery, and three probes, and a decent Users Manual. I paid $169 on Amazon, I could have got it for less on ebay. Its user friendly (so far).

I tested the scope on the output of two cheap inverters (12V to 120VAC) - both produced square waves with a gap in between. Also tested the output from a Klein probe (square wave) and a power supply transformer from a stereo (two AC traces on the same screen). Evidently its normal for the municipal AC waveform to be less than a pure sine wave.

 

[kiwi_outdoors]

The saga continues. Most recently it did the same thing, put itslef into Limp Mode first thing in the morning after being fine prior and 60+ deg F overnight (i.e., toasty) - without turning oit off I dorve it to the dealer at less than 60 mph I had an appointment) and turned it off in their forecourt. They found no cause of the error code, but did update some internal values in the PCM and TIPM.

The problem had been getting progressively more frequent since it started in April-May of this year, and I have back-to-back guests coming (and later, Thanksgiving) , so the Jeep needs to be fixed.

I did previously look at the PCM to TIPM harness and found no obvious wear points.

 

[kiwi_outdoors]

P0882 Symptoms and Considerations​

Symptoms etc.

First started in Idaho in April-May - in the cold and at altitude

Now occurs at high or low altitudes

Used to be triggered by cold weather (not so much any more)

Typically occurs on the first trip of the day - after cooling down overnight

Subsequent trips the same day are ok (unless short trips in cold weather)

Does this indicate that engine or transmission heat is a “fix”?

Used to be cleared by disconnecting the battery - now it takes more cycles of this action - sometimes up to 4 or 5 (includes shorting the battery cables together).

Why did this even work? It did clear the codes, but it was too quick for things to cool down or heat up enough to make a difference if the root cause was cool/heat related.

Check Engine light may or may not set with this issue!

Possisble Causes:

Short to ground in harness wiring

If so, why is it OK for all the rest of the day’s starts?

Break in harness wiring

If so, why is it OK for all the rest of the day’s starts?

Bad Relay

the plug-in relay tested ok

Dry soldered joint in TIPM

Dry soldered joint in PCM

Failing transmission solenoid coil inside the transmission (Overdrive?) - if so then how does it become OK after it warms up? (there are no shifting problems when not in Limp Mode)

I measured the coil’s resistance for all the solenoids between TCR Output and the solendoid - all were in the correct range (1.8~2 ohms)

Check ****** R.H. side assembly connector for corrosion <<not accessible, blocked by exhaust system

 

[KJowner]

Have you tried another relay? It may be on its last legs, after that I'd be looking for a dry joint. Intermittent faults are a pain.

 

[kiwi_outdoors]

Update:

as I said, the TIPM's plug-in relay on top tested ok (and I also swapped it with another relay). There is no internal micro-relay driving the on-top relay, the driver is solid state. The on-top fuse is also good.

I removed and disassembled the TIPM - found nothing obvious.

After reassembling and reinstalling the TIPM, on the first series of short test drives the Limp Mode fault was absent.

I did do a little testing of the voltage passing to and from the PCM and TIPM. Well - I confirmed that the TIPM can send volts back to the PCM (I cheated, and wrapped a copper wire beteen the relay's output-related pins). This test used a clamp-on wire probe that pierced the Yellow wire with the Orange stripe (there are two such wires, they carry a common voltage).

I tried to do the same type of test with the small wire taking the control signal from the PCM to the TIPM and had no luck. Those wires are tiny, so I'm not sure that I made probe-contact in either of the two Yellow/Brown wires (of which only one would have been relevant). I was leery of breaking the copper conductor inside each wire.

 

[kiwi_outdoors]

Today, one day later, two test drives yielded no limp mode, no P0882 code. Which makes diagnosing the problem problematical.

 

[KJowner]

Have to see how it goes, looks like you have found the source of the issue. Did you blast all the connections with switch cleaner?

 

[kiwi_outdoors]

Have to see how it goes, looks like you have found the source of the issue. Did you blast all the connections with switch cleaner?

I don't think I did anything useful disassembling the TIPM, other than confirm that the only relay involved is at the level of the fuses, there is no internal relay in the affected circuit (only a solid-state driver)

 

[kiwi_outdoors]

Update: the problem refuses to return.

I did finally identify the correct YL/BR wire, and examine its voltage. Voltage is high if things are working normally, same on the YL/OR wire. So now I have a baseline for voltages on the two main wires involved in the P0882 code.

Funny thing is, when I started this measuring today, I could have sworn that the YL/BR wire's voltage was low, but I might have had an iffy connection in my multimeter circuit or at the probe tip.

 

[kiwi_outdoors]

After two weeks of motoring bliss, the limp-mode problem is back. This first news instance - the battery disconnect trick cleared the problem (and any codes).

 

[KJowner]

Any scrapyards locally? I'd be tempted to try another TIPM.

 

[kiwi_outdoors]

Any scrapyards locally? I'd be tempted to try another TIPM.

Well, a used TIPM is not what I was thinking, but I will add it top the list - it would still need to be programmed for my VIN