Toadman
July 22nd, 2016, 03:33 AM
Have a 2007.5 2500 HD Duramax Allison with 250k kms and EFI Live 5 DSP, with DPF and EGR delete. Tows 12,000 lbs with additional weight in the box (heavy toyhauler with ATV on deck and lots of fuel/weight in truck box.), 23,000 lbs combined. Yes, over recommended weights. Typically only run Stock (1) Economy (2) or Tow (3) settings. Often play with Tow/Haul switch on hilly terrain to maximize fuel economy and lower RPM while not lugging the engine.
Problem: When engine (100*) and environment (28*C) is hot and towing heavy up a large hill the TCC solenoid lockup gets stuck OFF (P0741). Upon complete cool-down normal transmission operation resumes. This has happened twice, first time engine temp rose quickly to an overheat condition that was immediately cooled down. Second time temp was only slightly over normal cruzing operation.
Have dropped the pan, inspected wiring, changed internal and external filters/fluid and tested/verified (but ONLY at room temp) the TCC solenoid resistance of 5.2 ohms. No metal, minor clutch material visible in pan.
Question: Does EFI LIVE have any history of TCC lockup issues for the Allison when heavy towing and hot operating conditions?
Transmission gears work flawlessly, Torque Converter clutch "could" be going or the solenoid could have high temp issues.
Only have access to basic ODB2 code reader, not a graphing scan tool to check TCC lockup slip. Mechanic directed to ask this question, knowing that EFI Live was installed on the truck.
Thanks in advance for any advise or input.
Problem: When engine (100*) and environment (28*C) is hot and towing heavy up a large hill the TCC solenoid lockup gets stuck OFF (P0741). Upon complete cool-down normal transmission operation resumes. This has happened twice, first time engine temp rose quickly to an overheat condition that was immediately cooled down. Second time temp was only slightly over normal cruzing operation.
Have dropped the pan, inspected wiring, changed internal and external filters/fluid and tested/verified (but ONLY at room temp) the TCC solenoid resistance of 5.2 ohms. No metal, minor clutch material visible in pan.
Question: Does EFI LIVE have any history of TCC lockup issues for the Allison when heavy towing and hot operating conditions?
Transmission gears work flawlessly, Torque Converter clutch "could" be going or the solenoid could have high temp issues.
Only have access to basic ODB2 code reader, not a graphing scan tool to check TCC lockup slip. Mechanic directed to ask this question, knowing that EFI Live was installed on the truck.
Thanks in advance for any advise or input.