Circuit Description
The calibrations for the heater and A/C control are stored in EEPROM.
When the ignition is first turned On, the controller performs internal tests
on the EEPROM to determine if the EEPROM is programmed.
Conditions for Setting the DTC
| • | The test byte in EEPROM has an incorrect value (EEPROM not programmed.) |
| • | This fault is immediately recognized when the ignition is first
turned On. |
Action Taken When the DTC Sets
| • | Stores a DTC 52 in the controllers memory. |
| • | The heater and A/C control uses default values. |
Conditions for Clearing the DTC
| • | Programming the heater and A/C control. |
| • | The use of a scan tool. |
| • | A history DTC will clear after 20 consecutive ignition cycles
if the condition for the fault is no longer present. |
Diagnostic Aids
| • | Select PROGRAMMING from the HEATER and A/C CONTROL main menu. |
| • | Program the heater and A/C control. Follow the instructions on
the display screen. |
| • | If the heater and A/C control can not be programmed with the scan
tool, check all power and ground circuits to the controller. If OK, replace
the controller. Refer to
Control Assembly Replacement
. |
