POSSIBLE CAUSES
A/C HEATER CONTROL
INTERMITTENT WIRING PROBLEM
TEST
ACTION
APPLICABILITY
1
NOTE: All Actuator Circuit Test fault messages must be repaired before
diagnosing Overcurrent DTCs.
Turn the ignition on.
With the DRBIII
t in HVAC, System Tests, actuate the Actuator Circuit Test.
Does the DRBIII
t display any Actuator Circuit Test fault messages?
All
Yes
→ Return to the Heating & A/C symptom list and choose the
symptom(s).
Perform BODY VERIFICATION TEST - VER 1.
No
→ Go To 2
2
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Measure the resistance between the Recirculation Door Driver circuit and the Driver
Blend Door Driver circuit, the Passenger Blend Door Driver circuit, and the Mode
Door Driver circuit.
Measure the resistance between the Driver Blend Door Driver circuit and the
Passenger Blend Door Driver circuit and the Mode Door Driver circuit.
Measure the resistance between the Mode Door Driver circuit and the Passenger
Blend Door Driver circuit.
Is the resistance below 10K ohms on any of the circuits?
All
Yes
→ Repair the door driver circuits with a resistance below 10K ohms
for a short together.
Perform BODY VERIFICATION TEST - VER 1.
No
→ Go To 3
3
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Measure the resistance between the Common Door Driver circuit and the Recircu-
lation Door Driver circuit, the Driver Blend Door Driver circuit, the Passenger Blend
Door Driver circuit, and the Mode Door Driver circuit.
Is the resistance below 30.0 ohms on any of the circuits?
All
Yes
→ Go To 4
No
→ Go To 5
4
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Disconnect all door actuator harness connectors whose circuit resistance was below
30.0 ohms.
Measure the resistance between the Common Door Driver circuit and each applicable
door driver circuit.
Is the resistance below 10K ohms on any of the circuits?
All
Yes
→ Repair the door driver circuits with a resistance below 10K ohms
for a short to the Common Door Driver circuit.
Perform BODY VERIFICATION TEST - VER 1.
No
→ Replace all door actuators with a resistance below 30.0 ohms in
accordance with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
557
HEATING & A/C
BLEND OVERCURRENT (ACTIVE) - MTC —
Continued