Diesel Data: Automotive Repair

Test I: The Stoplamps Are On Continuously

PINPOINT TEST I: THE STOPLAMPS ARE ON CONTINUOUSLY

Normal Operation
When the brake pedal is applied, the stoplamp switch routes voltage to the smart junction box (SJB) through circuit 511 (LG). Voltage is also routed to the PCM through circuit 599 (PK/LG). The SJB then provides voltage to the stoplamps through circuits 1783 (RD/WH), 1374 (TN/LB), 1728 (LB/OG), and 1363 (WH/RD). Ground for the stoplamps is provided through circuit 1205 (BK).







This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Stoplamp switch
- SJB
- PCM


I1-I5:






I6-I7: