Test G

PINPOINT TEST G: NO COMMUNICATION WITH THE INSTRUMENT CLUSTER

Test G1:

Test G1-G2:

Test G3:

Normal Operation
Under normal operation the instrument cluster communicates interactively with other electronic modules using the standard corporate protocol (SCP) and the UART based protocol (UBP) communication networks. SCP communication is accomplished through the use of an unshielded, twisted pair cable data bus line, circuits 914 (TN/OG) and 915 (PK/LB). UBP communication is accomplished through a single data bus line, circuit 693 (OG). For additional information about the communications network, refer to Module Communications Network (Information Bus). With the key in the START/RUN position, the instrument cluster receives power from central junction box (CJB) fuse 21 (5A), circuit 489 (PK/BK). When in the RUN/ACC position, power is received from CJB fuse 15 (5A), circuit 295 (LB/PK). With the ignition in the OFF position, the instrument cluster receives its keep-alive power from the battery junction box (BJB) fuse 49 (15A), circuit 3049 (BK/LG). The instrument cluster grounding is accomplished through circuit 1203 (BK/LB) and the bulb grounding is accomplished through circuit 1205 (BK).

Possible Causes
- CJB fuse(s): 15 (5A) and 21 (5A)
- BJB fuse 15 (10A)
- circuit 295 (LB/PK) open or shorted to ground
- circuit 489 (PK/BK) open or shorted to ground
- circuit 1203 (BK/LB) open or shorted to power
- circuit 1205 (BK) open or shorted to power
- circuit 3049 (BK/LG) open or shorted to ground
- instrument cluster