How Do I Disable 2010 Dodge Journey Limp Mode?

[jshelto]

Vehicle went into limp mode due to P0765 trouble code. I replaced the solenoid pack and reset trouble code. Trouble code reappeared. Replaced ECU, reprogrammed ECU, ran transmission relearn procedure, and reset trouble code. Same trouble code reappeared. Replaced TIPM and reset trouble code. Trouble code reappeared. Bought the HP tuner and erased the trouble code from the ECU. Vehicle still goes into limp mode but the trouble code no longer appears. Vehicle runs fine. Just need to prevent it from going into limp mode. What else can I try? Thanks for the help.

[TransGo Robert]

You did not say what kind of transmission we are talking about, and with no engine size it is just a guess, but if it is a 41TE then the UD solenoid control wire wire or one of its terminals is compromised.

[jshelto]

Hi, I checked the wiring and measured for good continuity in the UD solenoid wiring. I also checked for electrical shorts. The coil resistance is within spec. For good measure I added conductive silver loaded grease into the connector sockets to ensure good electrical connection. Is there a way to use the HP Tuner to reprogram the ECU to not go into limp mode?

[Jim P 2.0]

Best thing to do is find the root cause of going into limp mode and correcting the root cause rather than trying to mask it, which is all ?turning off? the DTC does or ?turning off? limp mode would do. It?s not going to put it into limp mode just because, conditions are being met to give it reason to and that?s what needs to be addressed.

[jshelto]

Ideally, I agree. I have tried everything I can think of to no avail. Issue appears to be electrical noise from what I can tell and those are the hardest problems to track down. After countless hours of troubleshooting and several hundreds of dollars spent replacing solenoid pack, ECU, and TIPM I would rather erase limp mode and let something really break so I can then fix it. It is just a shame that the car is perfectly driveable except for going into limp mode. I turned off the DTC but am surprised that limp mode still engaged. Why does limp mode still engage if the DTC has been erased?

[TransGo Robert]

Hi, I checked the wiring and measured for good continuity in the UD solenoid wiring. I also checked for electrical shorts. The coil resistance is within spec. For good measure I added conductive silver loaded grease into the connector sockets to ensure good electrical connection. Is there a way to use the HP Tuner to reprogram the ECU to not go into limp mode?

All that testing is pretty useless because of the way the computer check the circuit integrity on those by briefly tuning ON or turning OFF the solenoid every 10 seconds and look to see how high the inductive spike goes. This is a super common code, and for the past 25 plus years of dealing with it, I have yet to find one person that can spot the problem with a DVOM unless it is a direct constant short to ground or a wide open circuit. The best way to go about diagnosing this in my opinion is to swap the wire at both ends with another solenoid wire. If the problem does not follow where you swap the wire then you have a bad solenoid again or more likely a bad replacement computer. The record on those (again assuming we are.working in a 41TE) for me was 3 bad Chrysler reman computers in a row with the same stupid code! They can't easily reman those because of the way they put the board in there, so they seem to just bench test them and then resell them as reman if no issue is detected. Since.this problem is pretty much always intermittent they miss it.

[jshelto]

The transmission is a 62TE. Wow, I was thinking that the computer wasn't the issue since I assumed there would be a very low probability of a defective re-manufactured computer giving me the same exact code. Based on your experience maybe I have another bad computer.

Thanks for the advice. I'll try measuring the spike with an o-scope tomorrow and the do the wire swap. Do you happen to know what spike parameters will trip the trouble code? Maybe reducing the spike by adding a small capacitor across the solenoid wire and the electrical return will work.

[Jim P 2.0]

Why does limp mode still engage if the DTC has been erased?

The DTC isn’t erased. It still triggers, just won’t show on a scanner. Just like turning “off” DTC’s doesn’t make a diesel operate properly with no DPF, etc. it’s still hard coded to go into limp mode if something is wrong.

[Jim P 2.0]

The transmission is a 62TE. Wow, I was thinking that the computer wasn't the issue since I assumed there would be a very low probability of a defective re-manufactured computer giving me the same exact code. Based on your experience maybe I have another bad computer.

Thanks for the advice. I'll try measuring the spike with an o-scope tomorrow and the do the wire swap. Do you happen to know what spike parameters will trip the trouble code? Maybe reducing the spike by adding a small capacitor across the solenoid wire and the electrical return will work.

Got it backwards, it’s looking for that spike to know “it’s ok”. Delaying/reducing with a capacitor/resistor would make it worse.

[TransGo Robert]

Got it backwards, it’s looking for that spike to know “it’s ok”. Delaying/reducing with a capacitor/resistor would make it worse.

Don't waste your time with the scope, unless you are the luckiest guy out there you won't catch it. Trust me, been there, done that, got the T-shirt. Just swap the wire and be done with it, you will know with 100% certainty if it's a wiring/terminal issue or not. Since it is a 62TE it is much less likely to be a bad reman computer. Still possible, but on those usually it is a wirring/terminal issue. Of course it could still be a bad reman computer, just nowhere as common as it is in the 4 speeds.

[jshelto]

Got it. Do you happen to know what a normal spike should look like? Amplitude, rise time, pulse width, etc...

[jshelto]

Don't waste your time with the scope, unless you are the luckiest guy out there you won't catch it. Trust me, been there, done that, got the T-shirt. Just swap the wire and be done with it, you will know with 100% certainty if it's a wiring/terminal issue or not. Since it is a 62TE it is much less likely to be a bad reman computer. Still possible, but on those usually it is a wirring/terminal issue. Of course it could still be a bad reman computer, just nowhere as common as it is in the 4 speeds.

Would setting the scope to trigger on the spike event increase the chance of recording it?

[Jim P 2.0]

Something else to check as well is the constant voltage supply from the transmission relay to the solenoid pack and ground wiring, make sure there isn’t any issues there.

[Jim P 2.0]

I know you mentioned replacing your TIPM but I once had an issue with a replacement TIPM for my 2012 Ram, a fault inside for the power relay to the transmission that would randomly cause similar issue, putting the transmission into limp mode and just got progressively worse. Put the original TIPM back in and all was well. So I would explore the power and ground feeding from the TIPM to the transmission as well, make sure no breaks in wires, etc.

[TransGo Robert]

Got it. Do you happen to know what a normal spike should look like? Amplitude, rise time, pulse width, etc...

It need to go above 40 volts or it will set the code once it happens enough. On a good working circuit the spike be between 42 and 45 volts usually. But again, I have spend hours and hours doing what you are thinking of doing and NEVER once was able to catch it even when I proved it swapping wires and then running a new one with terminals fixing it. But you do you.

[jshelto]

Don't waste your time with the scope, unless you are the luckiest guy out there you won't catch it. Trust me, been there, done that, got the T-shirt. Just swap the wire and be done with it, you will know with 100% certainty if it's a wiring/terminal issue or not. Since it is a 62TE it is much less likely to be a bad reman computer. Still possible, but on those usually it is a wirring/terminal issue. Of course it could still be a bad reman computer, just nowhere as common as it is in the 4 speeds.

Would it be possible/likely that the valve body is the root cause? I replaced the solenoid pack but not the valve body.

[TransGo Robert]

Would it be possible/likely that the valve body is the root cause? I replaced the solenoid pack but not the valve body.

No, this is strictly an electrical issue, nothing else.