DTC 73

DTC 73 EVO Actuator Circuit Open Or Shorted To Ground (For ABS With VES Only):

Circuit Description:
Battery voltage is supplied to EVO actuator terminal "A" when the EBCM/EBTCM commands the ABS enable relay "ON." Ground for the EVO actuator is provided through EBCM/EBTCM terminal "11" to actuator terminal "B". The EBCM/EBTCM controls the amount of current supplied to the EVO actuator bases on input from the wheel speed sensors and the steering wheel position sensor.

DTC Will Set When:
DTC 73 can be set before ABS initialization or above 16 km/h (10 mph). Before initialization, if the EBCM/EBTCM detects the EVO actuator control circuit is at ground, a malfunction exists. Above 16 km/h (10 mph), if the EVO actuator sense current is less than half the command current, a malfunction exists.

Action Taken:
A malfunction DTC is stored, ABS/VES is disabled, and the ABS indicator lamp is turned "ON" and power steering returns to full assist.

DTC Will Clear When:
DTC 73 setting conditions no longer exist and the ignition key is turned "OFF."

DTC Chart Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Checks for proper operation of the EVO actuator.
2. Checks for high resistance in the EVO actuator control circuit.
3. Checks for a short to ground in the EVO actuator control circuit.
4. Checks for high resistance in the EVO actuator control circuit.
5. Checks for a short to ground in the EVO actuator control circuit.
6. Checks for a short to ground in the EVO actuator.
7. Checks for an open in the EVO actuator.
8. Ensures open or short to ground is not due to physical damage of the circuitry.

Diagnostic Aids:
Ensure all ABS DTCs are diagnosed and corrected prior to clearing VES DTCs. Clearing VES DTCs will automatically clear ABS DTCs resulting in a loss of DTC history data.

An "Intermittent" malfunction is most likely caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation.

The frequency of the malfunction can be checked by using the enhanced diagnostic function of the Tech 1.

Any circuitry, that is suspected as causing the intermittent complaint, should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring connections or physical damage to the wiring harness.