Heating Ventilation Air Conditioning (HVAC)

CIRCUIT DESCRIPTION
The H-A/C control EEPROM contains the necessary software to run the heating and air conditioning program.

DTC WILL SET WHEN
With ignition in "RUN," the H-A/C control will detect this fault anytime the EEPROM experiences an internal fault.

ACTION TAKEN
DTC 27 will set. The ACAC system can operate in an erratic manner.

DTC WILL CLEAR WHEN
This fault will clear as soon as the EEPROM internal fault goes away.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test has you clear DTC(s) and recheck for DTC 27.

DIAGNOSTIC AIDS
Check connections at H-A/C control connector. Check B+ ignition and ground to the H-A/C control.