Front Seat Heater Control Unit Input Test (2016 2017 2018 2019 2020)

NOTE:

Before testing, check the No. B3-4 (50 A) fuse in the main under-hood fuse box.

Courtesy of HONDA, U.S.A., INC.

2. 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 look OK, go to step 3.

3. Reconnect the 14P connector to the control unit, and 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 4.

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
2	PNK	Vehicle ON mode	Measure the voltage to ground: There should be battery voltage.	Blown No. E5 (20 A) fuse in the passenger's under-dash fuse/relay box Faulty front seat heater relay An open or high resistance in the wire
9* 1	LT GRN	Vehicle ON mode	Measure the voltage to ground: There should be battery voltage.	Blown No. D22 (15 A) fuse in the driver's under-dash fuse/relay box Blown No. E20 (7.5 A) fuse in the passenger's under-dash fuse/relay box An open or high resistance in the wire
9* 2	LT GRN	Vehicle ON mode	Measure the voltage to ground: There should be battery voltage.	Blown No. D24 (7.5 A) fuse in the driver's under-dash fuse/relay box Blown No. H7 (10 A) fuse in the auxiliary under-dash fuse/relay box Faulty DC-DC converter Faulty DC-DC converter IG1 relay1 An open or high resistance in the wire
4	BRN	In all power modes	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G601) An open or high resistance in the ground wire

*1: Without auto idle stop system

*2: With auto idle stop system

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
1	RED	Vehicle ON mode, driver's seat heater ON mode	Measure the voltage to ground: There should be battery voltage.	Faulty driver's seat heater Poor ground (G601) or an open in the ground wire An open or high resistance in the wire
3	LT BLU	Vehicle ON mode, front passenger's seat heater ON mode	Measure the voltage to ground: There should be battery voltage.	Faulty front passenger's seat heater Poor ground (G604) or an open in the ground wire An open or high resistance in the wire

*1: Without auto idle stop system

*2: With auto idle stop system

4. Turn the vehicle to the OFF (LOCK) mode.

5. Disconnect the 14P connector from the control unit, and 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, the control unit must be faulty; replace it .

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
10	BLU	Under all conditions	Check for continuity between terminal 10 and climate control unit connector B (28P) terminal No. 10: There should be continuity.	An open in the B-CAN wire Faulty climate control unit
11	PNK	Under all conditions	Check for continuity between terminal 11 and climate control unit connector B (28P) terminal No. 9: There should be continuity.	An open in the B-CAN wire Faulty climate control unit
7	PUR	Under all conditions	Check for continuity between terminals No. 7 and No. 13: There should be continuity.	Faulty driver's seat cushion heater An open or high resistance in the wire
13	WHT	Under all conditions
6	GRN	Under all conditions	Check for continuity between terminals No. 6 and No. 12: There should be continuity.	Faulty front passenger's seat cushion heater An open or high resistance in the wire
12	BRN	Under all conditions