AC Compressor Will Not Engage - keywords air blower cooling hvac inoperative off warm temperature
| Subject: | AC Compressor Will Not Engage |
| Models: | 2007 Chevrolet Silverado |
| 2007 GMC Sierra |
| Equipped with Manual Air Conditioning ( RPO C67 ) |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some customers may state that the AC compressor will not engage at times. After initial inspection, there will be no codes in any module and the HVAC control head will show ac request reading " Yes' but the permission will read " Withheld ".
Recommendation/Instructions:
The Tech 2 may be showing the low pressure switch as closed when the switch may be actually open. A condition exists in the Tech 2 software that will read the low pressure switch backwards. The Tech 2 shows " Closed " when the switch is " Open" and shows " Open" when the switch is " closed ". A vehicle that is operating with-in normal pressures should show the parameter as " open " with this software glitch.
This PI will be updated when the concern is corrected.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
