Pinpoint Test E: All Control Illumination Does Not Dim

Instrument Cluster and Panel Illumination

Pinpoint Tests

Pinpoint Test E: All Control Illumination Does Not Dim

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 Smart Junction Box (SJB) sends a voltage reference signal through circuit VLN18 (BU/WH) to the instrument panel dimmer switch. The return signal is sent through circuit CLN27 (WH/BN) back to the SJB. The SJB then supplies a pulse-width modulated voltage signal to the dimmable illumination sources on circuit VLN04 (VT/GY).

- DTC B1247 (Panel Dim Switch Circuit Open) - a continuous DTC that sets when the SJB detects the dimmer switch input circuit is out of range.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Instrument panel dimmer switch
- SJB



PINPOINT TEST E: ALL CONTROL ILLUMINATION DOES NOT DIM

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

-------------------------------------------------
E1 CHECK CIRCUITS CLN27 (WH/BN) AND VLN18 (BU/WH) FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: SJB C2280d.
- Disconnect: Instrument Panel Dimmer Switch C2065.
- Ignition ON.
- Measure the voltage between the instrument panel dimmer switch C2065-4, circuit CLN27 (WH/BN), harness side and ground; and between the instrument panel dimmer switch C2065-1, circuit VLN18 (BU/WH), harness side and ground.




- Is any voltage present?

Yes
REPAIR the circuit in question. TEST the system for normal operation.

No
GO to E2.

-------------------------------------------------
E2 CHECK CIRCUITS CLN27 (WH/BN) AND VLN18 (BU/WH) FOR AN OPEN OR SHORT TO GROUND


- Measure the resistance between the instrument panel dimmer switch C2065-4, circuit CLN27 (WH/BU), harness side and the SJB C2280d-11, circuit CLN27 (WH/BU), harness side; and between the instrument panel dimmer switch C2065-4, circuit CLN27 (WH/BU), harness side and ground.




- Measure the resistance between the instrument panel dimmer switch C2065-1, circuit VLN18 (BU/WH), harness side and the SJB C2280d-12, circuit VLN18 (BU/WH), harness side; and between the instrument panel dimmer switch C2065-1, circuit VLN18 (BU/WH), harness side and ground.




- Is the resistance less than 5 ohms between the instrument panel dimmer switch and the SJB , and greater than 10,000 ohms between the instrument panel dimmer switch and ground?

Yes
GO to E3.

No
REPAIR the circuit in question. TEST the system for normal operation.

-------------------------------------------------
E3 CHECK THE INSTRUMENT PANEL DIMMER SWITCH


- Carry out the component test for the instrument panel dimmer switch.

- Is the instrument panel dimmer switch OK?

Yes
GO to E4.

No
INSTALL a new instrument panel dimmer switch. REFER to Instrument Panel Dimmer Switch Service and Repair. TEST the system for normal operation.

-------------------------------------------------
E4 CHECK FOR CORRECT SJB OPERATION


- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB 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 SJB. REFER to Body Control Systems. 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.

-------------------------------------------------