Tests AP: DTC B1555 - Ignition Run/Start Circuit Failure, DTC B2A20 - Ignition Stuck In Start Or U2472 - Unexpected Ignition St

PINPOINT TEST AP: DTC B1555 - IGNITION RUN/START CIRCUIT FAILURE, DTC B2A20 - IGNITION STUCK IN START OR U2472 - UNEXPECTED IGNITION STATE

Normal Operation
With the ignition switch in the START or RUN position, the instrument cluster (IC) receives voltage from the smart junction box (SJB) through circuit CBP36 (BU/BN). With the ignition switch in the OFF position, the instrument cluster (IC) receives its keep-alive voltage from the SJB through circuit SBP26 (YE/RD). The instrument cluster (IC) also monitors the ignition switch position data received from the SJB over the medium speed controller area network (MS-CAN) communication bus.

- DTC B1555 (Ignition Run/Start Circuit Failure) - is an on-demand DTC that sets in the instrument cluster (IC) when the SJB messaged ignition state indicates the ignition is in OFF/ACC and the hardwired RUN/START input indicates RUN/START for more than 5 seconds.
- DTC B2A20 (Ignition Stuck in START) - is a continuous memory DTC that sets in the instrument cluster (IC) when the instrument cluster (IC) detects the SJB messaged ignition state in start for greater than 15 seconds.
- DTC U2472 (Unexpected Ignition State) - is a continuous and on-demand DTC that sets in the instrument cluster (IC) when the cluster detects a discrepancy between the hardwired voltage input and the messaged ignition state inputs from the SJB. The SJB messaged input indicates RUN while the hardwired input indicates RUN/START for more than 5 seconds.

This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- Instrument cluster (IC)

AP1-AP2:

AP2-AP4:

AP5-AP6: