DTC B1168: Gauge Control Module Lost Communication with PCM (ENG Message); DTC B1169: Gauge Control Module Lost Communication with the PCM (A/T Message); DTC B1178: F-CAN Communication Line Error

WARNING: This page is about a different car, the 2009 Acura MDX, 2008 Acura MDX, and 2007 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

Clear the DTCs with the HDS.
Turn the ignition switch to LOCK (0), and then back ON (II).
Wait for 6 seconds or more.
Check for DTCs with the HDS.
Is DTC B1168, B1169, and/or B1178 indicated?

YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for loose or poor connection between the gauge control module and the PCM.
Check for Fuel and Emissions Systems DTCs with the HDS.
Are there any DTCs indicated?

YES - Go to the indicated DTCs, then recheck.

NO - Go to step 6.
Turn the ignition switch to LOCK (0).
Disconnect gauge control module connector A (12P).
Jump the SCS line with the HDS.
Disconnect PCM connector A (49P).
Connect the gauge control module connector A (12P) connector No. 6 and No. 12 terminals and body ground with jumper wires.

Fig 1: Identifying Gauge Control Module Connector Terminals 6 And 12 And Body Ground With Jumper Wires
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between body ground and PCM connector A (49P) No. 48 and No. 49 terminals individually.

Fig 2: Identifying Continuity Between Body Ground And PCM Connector Terminals 48 And 49
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), and recheck. If the indication goes away, replace the original PCM (see PCM REPLACEMENT ). If the DTC is still present, replace the gauge control module (see GAUGE CONTROL MODULE INPUT TEST ).

NO - Repair open in the wire.