A/C Heater Control Illumination Inoperative

A/C HEATER CONTROL ILLUMINATION INOPERATIVE

A/C Heater Control Illumination Inoperative:

POSSIBLE CAUSES
- Faults present in the cluster (MIC)
- (E16) Panel lamps driver circuit open
- Bulb(s) - filament open (single-zone HVAC module only)
- Cluster (MIC)
- A/C Heater control

Diagnostic Test

1. CHECK FOR DTCs IN THE CLUSTER (MIC)
Turn the ignition on.
With the DRBIII(R), read Cluster DTCs.

Q: Does the DRBIII(R) display any DTCs?

YES: Diagnose and repair the DTC(s). Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 2

2. TEST (E16) PANEL LAMPS DRIVER CIRCUIT USING A TEST LIGHT




Turn the Headlamp switch on.
Rotate the Cargo Dome switch to the full brightness setting.

CAUTION: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Using a 12-volt test light connected to ground, back probe the (E16) Panel Lamps Driver circuit in the A/C Heater Control C1 harness connector.

Q: Does the test light illuminate brightly?

YES: (Dual-Zone Systems)
Replace the A/C Heater Control. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
YES: (Single-Zone Systems)
Go To 3
NO: Go To 4

3. INSPECT THE INOPERATIVE BULB(S)
Turn the ignition off.
Remove the inoperative bulb(s) from the A/C Heater Control.

NOTE: If necessary, hold the bulb in front of a lamp to see the filament.

Inspect the bulb(s).

Q: Is each inoperative bulb Ok?

YES: Replace the A/C Heater Control. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Replace the inoperative bulb(s). Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

4. CHECK (E16) PANEL LAMPS DRIVER CIRCUIT FOR AN OPEN




Disconnect the A/C Heater Control C1 harness connector.
Disconnect the Cluster C1 harness connector.
Measure the resistance of the (E16) Panel Lamps Driver circuit between the A/C Heater Control C1 harness connector and the Cluster C1 harness connector.

Q: Is the resistance below 5.0 ohms?

YES: Replace the Cluster. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Repair the (E16) Panel Lamps Driver circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test