Clearing Trouble Codes

CLEARING FAULTS - ATC AND MTC SYSTEMS
For every fault that sets, the A/C-heater control maintains an independent count of the number of key cycles since the active DTC cleared, the odometer reading when the DTC set (ATC system), and the elapsed ignition on time that the DTC was active. When the number of key cycles (by parameter) reaches a global number, the system automatically clears all of the information associated with that DTC. A loss of battery voltage will also clear all active DTCs and associated data from memory. However, upon reconnecting the battery and activating the A/C-heater control ("Ignition" line going "HIGH"), the system will again evaluate all parameters and will set active DTCs for parameters outside of acceptable limits.

DTCs can also be cleared manually from the A/C-heater control (which also resets key cycle counters). Use a scan tool to clear DTCs stored in the A/C-heater control of the ATC system. To clear DTCs stored in the A/C-heater control of the MTC system, perform the following:

NOTE: An active DTC 33 will prevent the control from entering diagnostic mode and performing certain diagnostic functions. It will also prevent proper A/C mode switch and status indicator function. If this occurs, refer to A/C HEATER CONTROL WILL NOT ENTER DIAGNOSTIC MODE (MTC) for the diagnostic test procedure.




1. Turn the ignition to the On position.
2. Turn the blower motor control (1) to the lowest speed setting.
3. Press the A/C mode switch (2) down and turn the blower motor control to the Off position. Wait three seconds and then release the A/C switch.
4. When the A/C status indicator begins flashing DTCs, press the A/C mode switch down for three seconds and then release the A/C switch to clear the faults.