"D4" Indicator Light Does Not Come On (2.3CL & Odyssey)

WARNING: This page is about a different car, the 1998 Honda Odyssey, 1998 Honda Accord, and 1998 Acura 2.3CL. However, it is still accessible from the selected car via links, so may be relevant.

Turn ignition on. Ensure service connector shorting tool is not connected to service check connector. See Figure . Shift to "D4" position. If "D4" indicator light does not illuminate, go to next step. If "D4" indicator light illuminates, check for loose PCM harness connections. Replace PCM with a known-good unit if necessary and retest.
Turn ignition off. Disconnect 25-pin PCM harness connector "B". Using a DVOM, check for continuity between ground and 25-pin PCM harness connector "B", terminals No. 20 and 22 (Brown/Black wires). See Figure . If continuity is present, go to next step. If continuity is not present, repair open or poor connection in appropriate Brown/Black wire.
Turn ignition on. Measure voltage at 25-pin PCM harness connector "B", between terminals No. 1 (Yellow/Black wire) and No. 22 (Brown/Black wire), then between terminals No. 9 (Yellow/Black wire) and No. 20 (Brown/Black wire). If battery voltage is present, go to next step. If battery voltage is not present, repair open or short in appropriate Yellow/Black wire between PCM and engine compartment fuse/relay box.
Turn ignition off. Reconnect PCM harness connector. Connect a DVOM (backprobe) between 25-pin PCM harness connector "B", terminal No. 14 (Blue/Red wire) and terminals No. 20 or 22 (Brown/Black wires). Turn ignition on. Voltage should be present for 2 seconds. If DVOM indicates voltage as specified, go to next step. If no voltage was indicated, go to step 6) .
Check for an open or short in Blue/Red wire between PCM and gauge assembly. Repair as necessary. If no problem is found, repair faulty "D4" indicator bulb or gauge assembly printed circuit board.
Turn ignition off. Disconnect 32-pin PCM harness connector "A". Check Blue/Red wire for continuity between 32-pin PCM harness connector "A", terminal No. 14 and gauge assembly harness 16-pin connector terminal No. 3. If continuity is present, go to next step. If continuity is not present, repair open in Red/Blue wire.
Check for continuity between ground and 32-pin PCM harness connector "A", terminal No. 14 (Blue/Red wire). If continuity is not present, go to next step. If continuity is present, repair short to ground in Blue/Red wire.
Check for loose PCM harness connectors or faulty A/T gear position switch. Repair as necessary. If no problem is found, replace PCM with a known-good unit and retest.