Honda Odyssey Service Manual: Headlight Leveling Control Unit Input Test/Replacement

NOTE:

• Before testing, make sure that there is no DTCs and the combination light switch circuit is OK.

• Before testing, troubleshoot the multiplex integrated control unit first, using B-CAN System Diagnosis Test Mode A.

1. Remove the bolt (A) from the headlight leveling control unit bracket.

2. Disconnect the 16P connector (B) from the headlight leveling control unit (C).

3. Inspect the connector and socket 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 are OK, go to step 4.




4. With the connector still disconnected, do the following input tests:

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

   • If all the input tests prove OK, go to step 5.

   Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
   8	GRY	Ignition switch ON (II)	Measure the voltage to ground: There should be battery voltage.	Blown No. D21 (7.5 A) fuse in the passenger's under-dash fuse/relay box An open or high resistance in the wire
   16	BLK	In all ignition switch positions	Measure the voltage to ground:    There should be less than 0.2 V.	Poor ground (G403) An open or high resistance in the ground wire

5. Reconnect the connector to the headlight leveling control unit, and do the following input tests:

   • If any tests indicates a problem, find and correct the cause, then recheck the system.

   • If all the input tests prove OK, replace the headlight leveling control unit.

   NOTE: After replacing the control unit, do the headlight initial position learning procedure.

   Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
   7	GRN	Ignition switch ON (II),   headlight switch ON	Measure the voltage between terminals No. 7 and No. 6: There should be battery voltage.	Faulty headlight leveling motor An open or high resistance in the wire
   6	YEL
   14	BRN	Ignition switch ON (II),   headlight switch ON	Measure the voltage between terminals No. 14 and No. 6: There should be about 2 to 12 V.	Faulty headlight leveling motor An open or high resistance in the wire
   6	YEL
   5	PUR	Under all conditions	Measure the voltage between terminals No. 5 and No. 12: There should be about 5 V. Measure the voltage between terminals No. 5 and No. 3: There should be about 0.5 to 4.5 V.	Faulty front suspension stroke sensor An open or high resistance in the wire
   3	LT GRN
   12	PNK
   5	PUR	Under all conditions	Measure the voltage between terminals No. 5 and No. 12: There should be about 5 V. Measure the voltage between terminals No. 5 and No. 2: There should be about 0.5 to 4.5 V.	Faulty rear suspension stroke sensor An open or high resistance in the wire
   2	WHT
   12	PNK