P0125 Code after installing custom tune

[elad1591]

This issue has been resolved. It had to do with the way the rear O2s were being disabled. Thanks for everyone's input and help on this!

Tuner Information

Diablo Tuner Model: Trinity T1000
Software Revision: v.1.r.12

Vehicle Information

Make: Dodge
Model: Challenger R/T (Shaker Edition)
Year:2014
Engine: 5.7 Hemi
Transmission: Manual 6-Speed

Modifications:
- Modern Muscle 87mm Throttle Body
- Heartthrob 3” Cat Back Exhaust
- Kooks Long Tube Headers & High Flow Cats
- Gwatney Performance Innovation custom tune (Modified Diablo 93 Octane Tune).

Tune Facility Information:
Gwatney Performance Innovation (GPI), Jacksonville AR
1-888-388-3351
http://www.gwatneyperformance.com
Technician: Ryan Stevens - Head Calibrator at Gwatney Performance Innovation

Issue: P0125 Error Code after installing Gwatney Performance Innovation custom tune. In addition to the performance modifications to the tune the rear O2 sensors were also disabled. After driving the vehicle for about 30 miles the CEL came on. The code associated with the CEL is P0125 (P0125 Insufficient Coolant Temp For Closed Loop Fuel Control).

Troubleshooting>
1. I cleared the code and checked the coolant level. Coolant level was normal. Test drove the car. The CEL came back on after about 30 miles. The code associated with the CEL was P0125 .
2. I cleared the code and installed the Diablo 93 Octane tune. Test drove the car. The CEL came on after about 75 miles. The code associated with the CEL was P0420 (P0420 Catalyst System Efficiency Below Threshold (Bank1)). This code was expected due to the long tube headers and high flow cats. I test drove the car for an additional 50 miles. No other CEL codes were generated.
3. I cleared the P0420 code and reinstalled the GPI custom tune. I test drove the car. After about 30 miles the CEL came on. The code associated with the CEL was P0125.

I have attached the .drg


Thanks,

Dale

[Mike_Levy]

You have a stock thermostat? Or is it a Jet? That code comes up with the Jet very frequently.

[elad1591]

It has a stock thermostat.

[Mike_Levy]

It may be stuck open.

[elad1591]

Mike, I thought about that but I only receive the P0125 error when the custom tune is installed. The P0125 error code is not generated with any other tune (stock, Diablo 91 Octane, or Diablo 93 Octane). But I will check the thermostat.

[elad1591]

Additional Information:

Here are the Dyno results as the modifications were made:

Modification/HP/Peak HP RPM/Torque/AFR
*Stock - Baseline/334.9/5300/368.8/12.87
**CAI/340.7/5200/372.7/12.38
87MM TB/342.3/5250/377.0/12.81
Cat Back/344.5/5250/381.9/12.34
LT Headers and HF Cats/354.5/5400/376.1/12.81
Diablo 93 Octane Tune/364.3/5300/382.7/12.76
Custom Tune/366.0/5350/388.8/13.00

* - OEM R/T Air Box and Air Filter (The car came from the factory with the Shaker intake system. I put a stock R/T Air Box and Air Filter on the vehicle to get a baseline Dyno with it configured the same as a stock R/T without the Shaker intake system.)
** - OEM Shaker Intake System

[mikel]

post the tune please.

[elad1591]

I have uploaded the custom tune and the stock tune.

[elad1591]

I checked the thermostat this morning. It was NOT stuck open.

Tip: I was able to recover all but a few dribbles of the coolant by using some duct tape and a heavy duty plastic trash bag. I used the duct tape to secured the plastic bag up under the thermostat housing and a few other places. When I opened the thermostat housing and removed the thermostat the coolant ran into the bag. After reinstalling the thermostat, I removed the bag, took the coolant reservoir cap off and poured the coolant back in to the reservoir by cutting the tip off the one of the corners of the bag.

[Mike_Levy]

Its gotta be an issue with the tune then. Perhaps he turned on the fans too early. I can't check that as I don't have CMR access. Mike will have to do it on Monday.

[elad1591]

It is my understanding that the P0125 DTC has to do with the Air/Fuel mixture. When you start a cold engine, air/fuel mixtures are calculated using programming built into the PCM and ignores input from the engine sensors. As the engine warms up to operating temperature, the computer switches to Closed Loop mode, where it computes air/fuel mixtures based on actual engine conditions. The DTC code P0125 sets if the engine coolant temperature hasn't reached the required temperature for closed loop operation within a specified time. The set time varies based on start-up coolant temperature and the amount of airflow into the engine.

Does the vehicle remain in the Open Loop mode with this trouble code?

Is there anything in the tune that changes that set point or modifies the parameters that the PCM uses calculate it?

Can this the time be adjusted in the tune?

[elad1591]

I logged the time for the ECT to go from cold to normal operating temperature.

The logging was done under normal driving conditions.

Start temp/30C/86F
1 minute/43C/109F
2 minutes/47C/117F
3 minutes/53C/127F
4 minutes/63C/145F
5 minutes/72C/161F
6 minutes/85C/185F
7 minutes/91C/195F
8 minutes/96C/205
9 minutes/95C/203F - I'm guessing that the thermostat opened here
10 minutes/95C/203F

[Mike_Levy]

That took a LONG time to warm up. Something doesn't seem right. Neither of my SRT8s took anywhere near that long to heat up.



Mike, Did you get a chance to check his tune?

[elad1591]

Like I said in my previous post. I performed the logging under normal driving conditions. I started the car. Let it warm up for about a minute then took it out for the drive. Most of the driving was done at 55 plus MPH with the AC on.

I upgraded to 1r13 today. I loaded the Diablo 93 octane tune instead of the custom tune. I will check it again tomorrow and see if there is any difference.

[elad1591]

Time for car to go from cold to normal operating temperature - DiabloSport 93 Octane tune. The temps were almost identical to the test done with the Custom tune. Note: This tune has Not resulted in a P0125 trouble code.

Start temp/30C/86F
1 minute/41C/106F
2 minutes/47C/117F
3 minutes/53C/127F
4 minutes/61C/142F
5 minutes/73C/163F
6 minutes/84C/183F
7 minutes/90C/194F
8 minutes/96C/205F