Keyless Access System (Keyless Access Control Unit, Electric Steering Lock, and TPMS Control Unit) Input Test (2024 2025)

Keyless Access/TPMS Control Unit

NOTE:

Before testing, check for DTCs. If any DTCs are indicated, troubleshoot those DTCs first.
If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Refer to: BODY ELECTRICAL TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE B - CONTROL UNIT NOT COMMUNICATING (2021 2022 2023 2024 2025)
Before testing, make sure the fuses and relays associated with the system are OK.
Some models have the rear outer handle touch sensor. Perform the troubleshooting flow where applicable.

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

2. Disconnect the keyless access/TPMS control unit connectors.

KEYLESS ACCESS/TPMS CONTROL UNIT CONNECTOR A (32P) (female terminals):

KEYLESS ACCESS/TPMS CONTROL UNIT CONNECTOR B (36P) (female terminals):

KEYLESS ACCESS/TPMS CONTROL UNIT CONNECTOR C (20P) (female terminals):

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

Inspect the connectors 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 4.

With the connectors 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, then go to step 5.

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
C4	LT BLU	Under all conditions	Check for continuity between terminal C4 and data link connector (DLC) terminal No. 7:There should be continuity.	An open or high resistance in the wire
C4	LT BLU	Under all conditions	Check for continuity between terminal C4 and body ground:There should be no continuity.	A short to ground in the wire
C6	BLU	Under all conditions	Check for continuity between terminal C6 and data link connector (DLC) terminal No. 15:There should be continuity.	An open or high resistance in the wire
C6	BLU	Under all conditions	Check for continuity between terminal C6 and body ground:There should be no continuity.	A short to ground in the wire
B10	BLK	Press the engine start/stop switch	Measure the voltage to ground:There should be battery voltage.	Faulty engine start/stop switch An open or high resistance in the wire
B11B25	BRNLT GRN	Press the engine start/stop switch	Check for continuity between terminal B11 and B25:There should be continuity.	Faulty engine start/stop switch An open or high resistance in the wire
C5	LT GRN	Jump the SCS line with the HDS, disconnect PCM connector A (50P)	Check for continuity between terminal under-dash fuse/relay box connector F (18P) terminal No. 17 and PCM connector A (50P) terminal No. 46:There should be continuity.	An open or high resistance in the wire PCM
		Disconnect the under-dash fuse/relay box connector M (12P)	Check for continuity between terminal C5 and under-dash fuse/relay box connector M (12P) terminal No. 8:There should be continuity.	An open or high resistance in the wire
		Disconnect the under-dash fuse/relay box connector M (12P)	Check for continuity between terminal C5 and body ground:There should be no continuity.	A short to ground in the wire

Reconnect the connectors, 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, then go to step 6.

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
A1	RED	Under all conditions	Measure the voltage to ground:There should be battery voltage.	An open or high resistance in the wire
B18	WHT	Under all conditions	Measure the voltage to ground:There should be battery voltage.	An open or high resistance in the wire
A17	BLK	In all power modes	Measure the voltage to ground:There should be less than 0.2 V.	Poor ground An open or high resistance in the ground wire

*: With electric steering lock

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
B36	BLK	In all power modes	Measure the voltage to ground:There should be less than 0.2 V.	Poor ground An open or high resistance in the ground wire
B30	YEL	Vehicle ON mode	Measure the voltage to ground:There should be battery voltage.	Faulty IG1A relay An open or high resistance in the wire
B34	TAN	Vehicle ON mode	Measure the voltage to ground:There should be battery voltage.	Faulty IG1B relay An open or high resistance in the wire
B29	RED	Vehicle ON mode	Measure the voltage to ground:There should be battery voltage.	Faulty IG1B relay An open or high resistance in the wire
B27	TAN	Vehicle ON mode	Measure the voltage to ground:There should be battery voltage.	An open or high resistance in the wire
C14	WHT	Driver's door outer handle lock button pushed	Measure the voltage to ground:There should be less than 0.2 V.	Faulty driver's door outer handle Poor ground or an open in the ground wire An open or high resistance in the wire
C14	WHT	Driver's door outer handle lock button released	Measure the voltage to ground:There should be about 5 V.	Faulty driver's door outer handle A short to ground in the wire
C13	BLU	Front passenger's door outer handle lock button pushed	Measure the voltage to ground:There should be less than 0.2 V.	Faulty front passenger's door outer handle Poor ground or an open in the ground wire An open or high resistance in the wire
C13	BLU	Front passenger's door outer handle lock button released	Measure the voltage to ground:There should be about 5 V.	Faulty front passenger's door outer handle A short to ground in the wire
B1	YEL	Parking brake pedal pressed	Measure the voltage to ground:There should be less than 0.2 V.	Faulty parking brake switch Faulty parking brake switch ground An open or high resistance in the wire
B1	YEL	Parking brake pedal released	Measure the voltage to ground:There should be about 5 V.	Faulty parking brake switch A short to ground in the wire
C16	YEL	In-bed trunk lid outer handle switch pressed	Measure the voltage to ground:There should be less than 0.2 V.	Faulty in-bed trunk lid outer handle switch Poor ground or an open in the ground wire An open or high resistance in the wire
C16	YEL	In-bed trunk lid outer handle switch released	Measure the voltage to ground:There should be about 5 V.	Faulty in-bed trunk lid outer handle switch A short to ground in the wire

*: With electric steering lock

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
C10	BLU	Transmission in P position/mode	Measure the voltage to ground:There should be less than 0.2 V.	Faulty SBW shifter Faulty TCM An open or high resistance in the wire
C10	BLU	Transmission in any position/mode other than P	Measure the voltage to ground:There should be about 5 V.	Faulty SBW shifter Faulty TCM A short to ground in the wire
B3 *	LT GRN	Electric steering lock (LOCK)	Measure the voltage to ground:There should be about 5 V.	Faulty electric steering lock A short to ground in the wire
B3 *	LT GRN	Electric steering lock (UNLOCK)	Measure the voltage to ground:There should be less than 0.2 V.	Faulty electric steering lock An open or high resistance in the wire

*: With electric steering lock

Electric Steering Lock

NOTE:

SRS components are located in this area. Review the COMPONENT LOCATION INDEX , and GENERAL INFORMATION FOR SAFETY before doing repairs or servicing.
Before testing, make sure the fuses and relays associated with the system are OK.

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

7. Disconnect the electric steering lock 12P connector.

ELECTRIC STEERING LOCK 12P CONNECTOR (female terminals)

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

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, then go to step 9.

Reconnect the connector, 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 10.

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
3	RED	Under all conditions	Measure the voltage to ground:There should be battery voltage.	An open or high resistance in the wire

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
12	TAN	Vehicle ON mode	Measure the voltage to ground:There should be battery voltage.	An open or high resistance in the wire
7	BLK	In all power modes	Measure the voltage to ground:There should be less than 0.2 V.	Poor ground An open or high resistance in the ground wire
8	LT GRN	Electric steering lock (LOCK)	Measure the voltage to ground:There should be about 5 V.	Faulty keyless access/TPMS control unit A short to ground in the wire An open or high resistance in the wire
8	LT GRN	Electric steering lock (UNLOCK)	Measure the voltage to ground:There should be less than 0.2 V.	Faulty electric steering lock
5	PNK	Vehicle ON mode	Measure the voltage to ground:There should be battery voltage.	Faulty keyless access/TPMS control unit An open or high resistance in the wire A short to ground in the wire

10. If multiple failures are found on more than one control unit, KEYLESS ACCESS/TPMS CONTROL UNIT REMOVAL AND INSTALLATION . If input failures are related to a particular control unit, replace the control unit.