DTC Troubleshooting: B1178
  1. Check for continuity between the ECM/PCM connector A (44P) *1 (49P) *2 terminals No. 36 *1 (No. 3) *2 and No. 37 *1 (No. 4) *2 and body ground individually.
    *1:
    R18A2 engine and K20Z4 engine
    *2:
    L13Z1 engine

Are there continuity?
YES -
Replace the gauge control module (tach). ■
NO -
Repair an open in the wire.■

R18A2 engine and K20Z4 engine
L13Z1 engine