Navigation Communication Line Circuit Troubleshooting

WARNING: This page is about a different car, the 2011 Honda Pilot, 2010 Honda Pilot, and 2009 Honda Pilot. However, it is still accessible from the selected car via links, so may be relevant.

Operate the climate control system in several modes.
Is the climate control system OK?

YES - Go to step 2.

NO - Do the self-diagnostic function with the HDS (see HOW TO USE THE HDS TO CHECK FOR DTCS ) or climate control unit, (see HOW TO USE THE CLIMATE CONTROL UNIT SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS ). ■
Do the Navi system link, (see SYSTEM DIAGNOSTIC MODE )
Is the A/C or TALK/BACK icon red?

YES -
- A/C icon is red, go to step 3.
- If other icon is red, check navigation system error code (DTCs)
NO - Go to step 9
Turn the ignition switch to LOCK (0).
Disconnect navigation unit connector B (32P).
Disconnect climate control unit connector B (20P).
Check for continuity between the following terminals of climate control unit connector B (20P) and navigation unit connector B (32P).
20P: 32P:

No. 2: No. 4

No. 9: No. 21

No. 10: No. 20

Is there continuity?

YES - Go to step 7.

NO - Repair open in the wire(s) between the climate control unit and the navigation unit. ■

Fig 1: Checking Continuity Between Terminals Of Climate Control Unit Connector B (20P) & Navigation Unit Connector B (32P)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between body ground and the climate control unit connector B (20P) terminals No. 2, 9, and No. 10 individually.
Is there continuity?

YES - Repair short to body ground in the wire(s) between the climate control unit and the navigation unit. ■

NO - Go to step 8.

Fig 2: Checking Continuity Between Body Ground & Climate Control Unit Connector B (20P) Terminals No. 2, 9 & 10
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Reconnect climate control unit connector B (20P).
Disconnect navigation unit connector B (32P).
Connect the navigation unit connector B (32P) terminals No. 4, 20, and No. 21 with jumper wires.

Fig 3: Connecting Navigation Unit Connector B (32P) Terminals No. 4, 20 & 21 With Jumper Wires
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to ON (II).
Press and hold the AUTO button, then press and hold the OFF button.
Is the HEAT/VENT indicator solid with the remaining icons blinking?

YES - Do the Unit check with the navigation system (see UNIT CHECK (QUICK CHECK) ). ■

NO - Substitute a known-good climate control unit, and recheck. If the symptom goes away, replace the original climate control unit (see CLIMATE CONTROL UNIT REMOVAL/INSTALLATION ). ■

Fig 4: Identifying AUTO Button
Courtesy of AMERICAN HONDA MOTOR CO., INC.