B2628

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematics:

CIRCUIT DESCRIPTION
The I/P dimmer pot is a potentiometer. It is powered by the climate control panel (CCP). The CCP determines the level of dimming desired based on the voltage from the I/P dimmer pot. The CCP converts the I/P dimmer pot feedback voltage to a digital signal and puts it on the Class II communication bus.

CONDITIONS FOR RUNNING THE DTC
The CCP must be powered.

CONDITIONS FOR SETTING THE DTC
The feedback voltage is greater than 4.8V for more than 200 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
The dimming level is set to full brightness for all displays.

CONDITIONS FOR CLEARING THE MIL/DTC
The I/P dimmer pot short to B+ condition must be corrected.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. Tests for the proper operation of the circuit in the high voltage range.
4. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
5. Tests for a short to ground in the 5 volt reference circuit.