Front Blower Runs At Only One Speed (ATC)

*FRONT BLOWER RUNS AT ONLY ONE SPEED (ATC)

For a complete wiring diagram Consult Diagrams/Electrical





Diagnostic Test

1. CHECK (C56) FRONT BLOWER MOTOR CONTROL CIRCUIT FOR A SHORT TO GROUND
CAUTION: The A/C Heater Control will clamp the blower speed if the PCM disables A/C compressor operation due to low or high A/C pressure, immanent overheat detection, or an overheat condition. Verify that none of these conditions exist before diagnosing blower concerns.

Turn the ignition off.
Disconnect the Front Blower Power Module C1 harness connector.
Disconnect the A/C Heater Control harness connector.
Measure the resistance between ground and the (C56) Front Blower Motor Control circuit.
Does the ohm meter read open circuit?

Yes

- Go To 2

No

- Repair the (C56) Front Blower Motor Control circuit for a short to ground.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.

2. CHECK A/C HEATER CONTROL OPERATION
Reconnect all previously disconnected components.
Turn the ignition on.
With the scan tool, check the data display for the Front Blower with the A/C Heater Control in the lowest and highest settings.
Does the scan tool display approximately 32.0% in the lowest setting and 100% in the highest setting?

Yes

- Replace the Front Blower Power Module.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.

No

- Replace the A/C Heater Control.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.