B2624

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
The body control module (BCM) supplies voltage to the instrument panel dimmer switch through the instrument panel dimmer switch signal circuit. The dimmer switch varies the voltage and returns the new voltage to the BCM through the dimmer switch signal return circuit. The BCM uses this voltage to determine the illumination level of the instrument panel lamps.

CONDITIONS FOR RUNNING THE DTC
The park lamp input to the BCM is active (park or headlamps on).

CONDITIONS FOR SETTING THE DTC
Any of the following conditions will set this DTC:
^ The dimmer switch signal is open for 5 seconds.
^ The dimmer switch signal return is open for 5 seconds.
^ The dimmer switch signal return is shorted to battery for 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
The illumination of the instrument panel lamps is forced to full intensity.

CONDITIONS FOR CLEARING THE DTC
^ A current DTC B2624 will clear when the malfunction is no longer present.
^ All BCM history codes clear after 100 ignition cycles with no current codes active during the 100 ignition cycles.

DIAGNOSTIC AIDS
^ If the dimmer switch signal return becomes shorted to ground, no DTC will be set but the instrument panel lamps will be at full intensity.
^ If the DTC is a history DTC, the problem may be intermittent. Try performing the tests while wiggling the wiring and connectors. This can often cause the malfunction to appear.

TEST DESCRIPTION
The number(s) below refer to the step number(s) on the diagnostic table.
2. The normal operating voltage of the instrument panel dimmer switch is, 5-11.5 volts.
3. If the value is above 11.5 volts, with the sensor disconnected, an open or short to voltage exists. If the value is below, 5 volts, a short to ground exists.