Test F: The Control Illumination Does Not Dim

PINPOINT TEST F: THE CONTROL ILLUMINATION DOES NOT DIM

Normal Operation
The smart junction box (SJB) monitors the input from the instrument panel dimmer switch by sending a voltage reference signal through circuit CLN27 (WH/BN) to the instrument panel dimmer switch. The return signal is sent through circuit CLN17 (BN) back to the SJB. Based on the return signal intensity, the SJB sends a pulse-width modulated (PWM) voltage signal to the dimmable illumination sources. If the SJB detects a concern with the circuitry to the instrument panel dimmer switch, the SJB defaults the backlighting to a full intensity level.

- DTC B2121 (Illumination Switch Short to Battery) - is a continuous and on-demand DTC that sets when the SJB detects a short to voltage on the illumination dimmer switch circuit.
- DTC B2132 (Dimmer Switch Circuit Short to Gnd) - is a continuous and on-demand DTC that sets when the SJB detects a short to ground on the dimmer switch circuit.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Instrument panel dimmer switch
- SJB

F1-F3:

F3-F5:

F6: