D Indicator Circuit Troubleshooting

Turn the ignition switch ON (II), and watch the D indicator.
Does the D indicator come on and stay on?
1. YES -Go to step 2.
2. NO -If the light comes on for about 2 seconds and then goes off, it's OK. If it does not come on at all, go to step 12.
Make sure the Honda diagnostic system (HDS) is not connected to the DLC.
Turn the ignition switch OFF.
Disconnect TCM connector A (26P).
Turn the ignition switch ON (II).
Measure the voltage between TCM connector terminal A20 and body ground.

Fig 1: Measuring Voltage Between TCM Connector A (26P) Terminal A20 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there voltage?
1. YES -Repair a short to power in the wire between TCM connector terminal A20 and the gauge assembly.
2. NO -Go to step 7.
Turn the ignition switch OFF.
Reconnect TCM connector A (26P).
Turn the ignition switch ON (II).
Shift to any position other than the D position.
Measure the voltage between TCM connector terminal A9 and body ground.

Fig 2: Measuring Voltage Between TCM Connector A (26P) Terminal A9 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there voltage?
1. YES -Faulty TCM or the gauge assembly.
2. NO -Check for short to ground in the wire between TCM connector terminal A9 and the transmission range switch. If the wire is OK, check the transmission range switch.
Shift to the D position, and watch the D indicator.
Does the D indicator come on?
1. YES -Check for loose terminal fit in the TCM connectors, and recheck the D indicator several times. If the problem is intermittent, substitute a known-good TCM (see HOW TO TROUBLESHOOT CIRCUIT AT THE TCM ), and recheck. If the light then works OK every time, replace the original TCM.
2. NO -Go to step 13.
Turn the ignition switch OFF.
Disconnect TCM connector A (26P).
Check for continuity between TCM connector terminal A4 and body ground, and between terminal A17 and body ground.

Fig 3: Checking Continuity Between TCM Connector Terminal A4, A17 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity between each terminal and ground?
1. YES -Go to step 16.
2. NO -Repair an open in the wire(s) between TCM connector terminal A4 or A17 and ground (G101), or repair poor ground (G101).
Turn the ignition switch ON (II).
Measure the voltage between TCM connector terminals A4 and A12, and between terminals A17 andA25.

Fig 4: Measuring Voltage Between TCM Connector Terminals A4 And A12 And Between Terminals A17 And A25
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES -Go to step 18.
2. NO -Repair an open or short in the wire between TCM connector terminals A12 or A25 and the under-dash fuse/relay box.
Turn the ignition switch OFF.
Reconnect TCM connector A (26P).
Connect the multimeter between TCM connector terminals A20 and A4.

Fig 5: Connecting Multimeter Between TCM Connector A (26P) Terminals A20 And A4
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch ON (II), and check for the voltage.
Is there voltage for at least 2 seconds?
1. YES -Check for an open in the wire between TCM connector terminal A20 and the gauge assembly. If the wire is OK, check for a faulty D indicator bulb or a faulty printed circuit board in the gauge assembly.
2. NO -Go to step 22.
Turn the ignition switch OFF.
Disconnect TCM connector A (26P).
Check for continuity between TCM connector terminal A20 and gauge assembly connector terminal C10.

Fig 6: Checking Continuity Between TCM Connector A (26P) Terminal A20 And Gauge Assembly Connector Terminal C10
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES -Check for loose terminal fit in the TCM connectors. Check the transmission range switch. If necessary, substitute a known-good TCM (see HOW TO TROUBLESHOOT CIRCUIT AT THE TCM ), and recheck.
2. NO -Repair an open in the wire between TCM connector terminal A20 and gauge assembly.