Pinpoint Test C: The Climate Control Illumination Is Inoperative
Instrument Cluster and Panel Illumination
Pinpoint Test C: The Climate Control Illumination Is Inoperative
Refer to Wiring Diagram Set 71, Cluster and Panel Illumination for schematic and connector information. Diagrams By Number
Normal Operation
With the parking lamps on, the Lighting Control Module (LCM) supplies a variable Pulse Width Modulated (PWM) voltage to the HVAC module (automatic temperature control) or to the climate control assembly (manual temperature control) on circuit 484 (OG/BK). The HVAC module and the climate control assembly (manual temperature control) illumination is grounded through circuit 57 (BK). The Driver Door Module (DDM) also generates a secondary variable voltage which is distributed to the HVAC module on circuit 19 (LB/RD).
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- HVAC module (automatic temperature control)
- Climate control assembly (manual temperature control)
- DDM
PINPOINT TEST C: THE CLIMATE CONTROL ILLUMINATION IS INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
NOTE: Verify the climate control assembly bulb is OK before starting diagnostics.
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C1 CHECK CIRCUIT 484 (OG/BK) FOR AN OPEN
- Disconnect: HVAC Module C228b (Automatic Temperature Control).
- Disconnect: Climate Control Assembly C294d (Manual Temperature Control).
- With the parking lamps on, rotate the instrument panel dimmer switch to the maximum brightness position.
- Measure the voltage between the HVAC module (automatic temperature control) C228b-14, circuit 484 (OG/BK), harness side and ground; or between the climate control assembly (manual temperature control) C294d-1, circuit 484 (OG/BK), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
If equipped with automatic temperature control, GO to C2.
If equipped with manual temperature control, GO to C3.
No
REPAIR the circuit. TEST the system for normal operation.
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C2 CHECK CIRCUIT 19 (LB/RD) FOR VOLTAGE
- Measure the voltage between the HVAC module C228a-19, circuit 19 (LB/RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to C6.
No
GO to C4.
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C3 CHECK CIRCUIT 57 (BK) FOR AN OPEN
- Disconnect: Negative Battery Cable.
- Measure the resistance between the climate control assembly C294d-2, circuit 57 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new climate control assembly module. TEST the system for normal operation.
No
REPAIR the circuit. TEST the system for normal operation.
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C4 CHECK CIRCUIT 19 (LB/RD) FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Place the headlamp switch in the OFF position.
- Disconnect: DDM C501b.
- Measure the resistance between the HVAC module C228a-19, circuit 19 (LB/RD), harness side and the DDM C501b-14, circuit 19 (LB/RD), harness side; and between the HVAC module C228a-19, circuit 19 (LB/RD), harness side and ground.
- Is the resistance less than 5 ohms between the HVAC module and the DDM, and greater than 10,000 ohms between the HVAC module and ground?
Yes
GO to C5.
No
REPAIR the circuit. TEST the system for normal operation.
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C5 CHECK FOR CORRECT DDM OPERATION
- Ignition OFF.
- Disconnect all the DDM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the DDM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new DDM. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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C6 CHECK FOR CORRECT HVAC MODULE OPERATION
- Ignition OFF.
- Disconnect all the HVAC module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the HVAC module connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new HVAC module. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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