Test C: One Or More Smart Junction Box (SJB) Controlled Illumination Source(s) Is Inoperative

PINPOINT TEST C: ONE OR MORE SMART JUNCTION BOX (SJB) CONTROLLED ILLUMINATION SOURCE(S) IS INOPERATIVE

C1-C4:

C4-C5:

C6-C8:

C8-C9:

C10-C11:

Normal Operation - Dimmable Backlighting
With the parking lamps on, a voltage signal is supplied to the instrument panel dimmer switch through circuit 1036 (BN/WH) from the SJB. The dimmer switch passes this voltage through a variable resistor and then returns the signal to the SJB on circuit 1035 (OG/RD). The SJB uses the return signal to determine the backlighting intensity desired by the operator. A pulse-width modulated (PWM) signal is sent from the SJB to each of the dimmable backlights maintaining the operator's desired level of lighting intensity.

DTC B2027 - sets when the LED backlighting detects a short to voltage or ground.

Normal Operation - Non-Dimmable Backlighting
When the ignition switch is placed in the ACCY or the ON position, a voltage signal is supplied to the SJB. The SJB activates the accessory delay relay, supplying voltage to the non-dimmable backlights.

Possible Causes
- Fuse
- Circuit 19 (LB/RD) open or short to ground
- Circuit 203 (OG/LB) open or short to ground
- Circuit 293 (OG/RD) open or short to ground
- Circuit 333 (YE/RD) open or short to ground
- Circuit 984 (YE/LB) open or short to ground
- Circuit 985 (RD/LB) open or short to ground
- Circuit 1205 (BK) open
- Circuit 1403 (BK/WH) open or short to ground
- Circuit 1425 (GY/WH) open or short to ground
- Circuit 2023 (YE/LB) open or short to ground
- Circuit 2029 (LB/WH) open or short to ground
- Circuit 2030 (YE/WH) open or short to ground
- Illuminated component
- Clockspring
- Accessory delay relay
- Speed control switch
- SJB