DTC B2965: Rear Communication Failure

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2017 Honda Odyssey, 2016 Honda Odyssey, 2015 Honda Odyssey, 2014 Honda Odyssey, and 2013 Honda Odyssey. 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 to ON (II).
Do the Self-Diagnostic Function with the HDS (see HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS ).
Check for DTCs.
Is DTC B2965 indicated?

YES -Go to step 5.

NO -Intermittent failure. Check for loose wires or poor connections in the rear A/C control panel, rear A/C control unit, and climate control unit circuit.
Turn the ignition switch to LOCK (0).
Disconnect rear A/C control unit connector B (5P) and the rear A/C control panel 5P connector.
Turn the ignition switch to ON (II).
Measure the voltage between body ground and rear A/C control unit connector B (5P) terminal No. 1, rear A/C control panel 5P connector terminal No. 2 individually.

Fig 1: Measuring Voltage Between Body Ground And Rear A/C Control Unit Connector Terminal Rear A/C Control Panel Connector Terminal
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: Identifying Rear A/C Control Unit Connector B (5P)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 9.

NO -Repair an open in the wire between the No. C26 (7.5 A) fuse in the driver's under-dash fuse/relay box and the rear A/C control unit, or an open in the wire between the No. C26 (7.5 A) fuse in the driver's under-dash fuse/relay box and the rear A/C control panel.
Turn the ignition switch to LOCK (0).
Check for continuity between body ground rear A/C control unit connector B (5P) terminal No. 3 and rear A/C control panel 5P connector terminal No. 4 individually.

Fig 3: Checking Continuity Between Body Ground Rear A/C Control Unit And Rear A/C Control Panel Connector Terminal
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 4: Identifying Rear A/C Control Unit Connector B (5P)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 11.

NO -Check for an open in the wire between the rear A/C control unit and body ground, or an open in the wire between the rear A/C control panel and body ground. If the wire is OK, check for poor ground at G652 (see RIGHT SIDE WIRE HARNESS (RIGHT REAR BRANCH) (M) ), or G701 (see ROOF WIRE HARNESS (WITH MOONROOF) (J) ).
Disconnect climate control unit connector A (28P).
Check for continuity between rear A/C control unit connector B (5P) terminal No. 5 and climate control unit connector A (28P) terminal No. 11, and between climate control unit connector A (28P) terminal No. 11 and rear A/C control panel 5P connector terminal No. 3.

Fig 5: Checking Continuity Between Rear A/C Control Unit Connector And Rear A/C Control Panel Connector Terminal
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 13.

NO -Repair an open in the wire between the climate control unit and the rear A/C control unit, or an open in the wire between the climate control unit and the rear A/C control panel.
Check for continuity between climate control unit connector A (28P) terminal No. 11 and body ground.

Fig 6: Checking Continuity Between Climate Control Unit Connector Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to body ground in the wire between the climate control unit and the rear A/C control unit, or a short to body ground in the wire between the climate control unit and the rear A/C control panel.

NO -Substitute a known-good rear A/C control unit (see REAR A/C CONTROL UNIT REPLACEMENT ) or rear A/C control panel (see REAR MODE CONTROL MOTOR REPLACEMENT ), and recheck. If the symptom/indication goes away, replace that original component that was substituted. If the symptom/indication still exist, replace the other component.