With OBD II Scantool/Honda PGM Tester
When the TCM senses an abnormality in the input or output systems, the (D) indicator light in the gauge assembly will blink. When the 16P Data Link Connector (DLC) (located to the lower left of the glove compartment) is connected to the OBD-II Scan Tool or Honda PGM Tester as shown, the scan tool or tester will indicate the Diagnostic Trouble Code (DTC) when the ignition switch is turned ON (II).
When the (D) indicator light has been reported on, connect the OBD-II Scan Tool conforming to SAE J1978 or Honda PGM Tester to the DLC (16P) to the lower left of the glove compartment. Turn the ignition switch on (II), and observe the DTC on the screen of the OBD-II Scan Tool or Honda PGM Tester. After determining the DTC, refer to the electrical system Symptom-to-Component Chart.
NOTE: See the OBD-II Scan Tool or Honda PGM Tester user's manual for specific instructions.
Some PGM-FI problems will also make the (D) indicator light come on. After repairing the PGM-FI system, disconnect the CLOCK fuse (7.5 A) in the under-hood fuse/relay box for more than 10 seconds to reset the TCM memory, then recheck.
NOTE: Disconnecting the BACK UP fuse also cancels the radio preset stations and the clock setting. Make note of the radio presets before removing the fuse so you can reset them.