DTC B1906: Immobilizer-Keyless Control Unit Lost Communication With Gauge Control Module (A/T Message)

WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If you are troubleshooting multiple DTCs be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

Clear the DTCs with the HDS.
Turn the ignition switch to LOCK (0) and then back to ON (II).
Wait for at least 6 seconds.
Check for DTCs with the HDS.
Is DTC B1906 indicated?

YES -Go to step 5.

NO -Intermittent failure, the system is OK at this time. Check for loose or poor connections between the gauge control module and the immobilizer-keyless control unit.
Turn the ignition switch to LOCK (0).
Connect the HDS to the data link connector, then turn the ignition switch to ON (II).
Select the BODY ELECTRICAL menu, then enter the UNIT INFORMATION.
Check the condition of the gauge control module from the CONNECTED UNITS list.
Is NOT AVAILABLE indicated?

YES -Go to step 9.

NO -Go to step 10.
Do the gauge control module input test (see GAUGE CONTROL MODULE INPUT TEST ).
Are all inputs OK?

YES -Replace the gauge control module (see GAUGE CONTROL MODULE REPLACEMENT ).

NO -Repair the faulty input, then recheck the DTCs.
Turn the ignition switch to LOCK (0).
Remove the gauge control module but leave it connected, then turn the ignition switch to ON (II).
Measure the voltage between body ground and gauge control module 32P connector terminals No. 15 and No. 16 individually.

Fig 1: Measuring Voltage Between Body Ground And Gauge Control Module 32P Connector Terminals No. 15 And No. 16
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 13.

NO -Check the No. 1 (15 A) and the No. 22 (7.5 A) fuses in the under-dash fuse/relay box. If the fuse is blown, replace the fuse and recheck the DTCs. If the fuses are OK, repair an open in the wire between the under-dash fuse/relay box and the gauge control module.
Measure the voltage between body ground and gauge control module 32P connector terminals No. 1 and No. 5 individually.

Fig 2: Measuring Voltage Between Body Ground And Gauge Control Module 32P Connector Terminals No. 1 And No. 5
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there less than 0.2 V?

YES -Go to step 14.

NO -Repair an open or high resistance in the wire or poor ground (G501).
Turn the ignition switch to LOCK (0).
Disconnect under-dash fuse/relay box connector Q (16P).
Check for continuity between under-dash fuse/relay box connector Q (16P) terminal No. 3 and gauge control module 32P connector terminal No. 17.

Fig 3: Checking Continuity Between Under-Dash Fuse/Relay Box Connector Q (16P) Terminal No. 3 And Gauge Control Module 32P Connector Terminal No. 17
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Replace the gauge control module (see GAUGE CONTROL MODULE REPLACEMENT ).

NO -Repair an open in the wire.