Interlock Control Unit Input Test

Disconnect the 8P connector from the interlock control unit

Inspect the connector and connector terminals to be sure they are all making good contact.

If the terminals are bent, loose, or corroded, repair them as necessary, and recheck the system.

If the terminals look OK, make the following input test at the connector.

If a test indicates a problem, find and correct the cause, then recheck the system.

If all the input tests prove OK, substitute a known-good control unit, and recheck the system. If the check is OK, the control unit must be faulty; replace it.

NOTE: If the shift lock solenoid clicks when the ignition switch is turned ON (II) and brake pedal is depressed with the shift lever in [P] position, the shift lock system is electronically normal; if the shift lever cannot be shifted from [P] position, test the A/T gear position switch.

Fig 1: Identifying 8P Connector And Interlock Control Unit

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: Identifying Interlock Control Unit Connector (8P)

Courtesy of AMERICAN HONDA MOTOR CO., INC.

INTERLOCK CONTROL UNIT CONNECTOR (8P) TERMINAL REFERENCE

Terminal Number	Wire Color	Test Condition	Test: Desired Result	Possible Cause (If result is not obtained)
1	WHT/BLU	Ignition switch turned to ACC (I), ignition key pushed all the way in	Check for voltage to ground: There should be battery voltage.	Blown No. 48 (30A) fuse in the under-hood fuse/relay box Blown No. 33 (7.5 A) fuse in the under-dash fuse/relay box Faulty steering lock assembly (key interlock solenoid) An open in the wire
2	YEL	Ignition switch turned ON (II)	Check for voltage to ground: There should be battery voltage.	Blown No. 19 (7.5 A) fuse in the under-dash fuse/relay box Faulty steering lock assembly (key interlock solenoid) An open in the wire
3	YEL/BLK	Ignition switch turned ON (II)	Check for voltage to ground: There should be battery voltage.	Blown No. 19 (7.5 A) fuse in the under-dash fuse/relay box Faulty shift lock solenoid An open in the wire
4	BLK	Under all conditions	Check for continuity to ground: There should be continuity.	Poor ground (G401, G402) An open in the wire
5	WHT	Ignition switch turned to ACC (I), ignition key pushed all the way in	Check for voltage to ground: There should be battery voltage.	Blown No. 48 (30 A) fuse in the under-hood fuse/relay box Blown No. 33 (7.5 A) fuse in the under-dash fuse/relay box Faulty steering lock assembly (key interlock solenoid) An open in the wire
6	BLK/BLU	Shift lever in [P]	Check for continuity to ground: There should be continuity.	Faulty A/T gear position switch Poor ground (G401, G402) An open in the wire
8	WHT/BLK	Shift lever in [P] and push button pressed	Check for continuity to ground: There should be continuity.	Faulty parking pin switch Short to ground
8	WHT/BLK	Shift lever in [P] and push button released	Check for continuity to ground: There should be no continuity.	Faulty parking pin switch Short to ground
Reconnect the interlock control unit 8P connector.
7	WHT/RED	Ignition switch ON (II) and brake pedal pushed	Check for voltage to ground: There should be 1 V or less.	Faulty brake switch Faulty throttle position (TP) sensor Faulty PCM An open in the wire
7	WHT/RED	Ignition switch ON (II), brake pedal and accelerator pedal depressed at the same time	Check for voltage to ground: There should be battery voltage.