Hybrid Two-Mode A/C Blows Warm Air, A/C Compressor Does Not Engage with DTC B101D and U0073 Set (Reprogram ACCM)
| Subject: | Hybrid Two-Mode A/C Blows Warm Air, A/C Compressor Does Not Engage With DTC B101D and U0073 Set, (Reprogram ACCM) |
| Models: | 2008 Chevrolet Tahoe Hybrid |
| 2008 GMC Yukon Hybrid |
| with 6.0L Engine (VIN 5 -- RPO LFA) |
| with Automatic Temperature Control HVAC System (RPO CJ2) |
Condition
Some customers may comment that the air conditioning (A/C) blows warm air and/or the A/C compressor does not engage.
Upon investigation, the technician may find that Diagnostic Trouble Code (DTC) B101D--ECU Hardware Performance Internal Electronic Failure and U0073- Control Module Communication Bus Off has been set and the A/C compressor will not engage.
Cause
This condition may occur when underhood battery power is removed from the ACCM. The ACCM software calibration may not retain the current values on power-up.
Correction
Important: Verify that the 12-volt battery has a battery charge of 12 to 16 volts. The battery must be able to maintain a charge during programming. Only use approved Midtronics 165-PCS charger or equivalent to maintain proper battery voltage during programming. The J2534 MDI will reprogram the modules in less time than the Tech 2® scan tool. Clear all DTC codes after programming.
An updated Air Conditioning Compressor Module (ACCM) Calibration is now available to address these concerns. Reprogram the ACCM with the updated software calibration files using the TIS2WEB Service Programming System (SPS) application.
Warranty Information
For vehicles repaired under U.S. warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
D9740* | Air Conditioning Compressor Module Programming with SPS | 0.4 hr |
*This labor operation number is for bulletin use only. This number will not be published in the Labor Time Guide. | ||
