Keyless Access System (Keyless Access Control Unit and TPMS Control Unit) Input Test (2018 2019 2020)

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2020 Acura RLX, 2019 Acura RLX, 2018 Acura RLX, 2017 Acura RLX, and 2016 Acura RLX. However, it is still accessible from the selected car via links, so may be relevant.

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 .
Before testing, make sure the No. B2-2, No. B3-1, No. B3-2, No. B3-4, and No. B3-6 fuses are OK.
Before testing, make sure the No. C5, No. C16, and No. C19 fuses are OK.
Before testing, make sure the No. D12 and No. D30 fuses 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.

NOTE: All connector views are shown from the wire side of the female terminals.

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

3. 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.

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, 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 K LINE 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 K LINE wire
C6	YEL	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 L-LINE wire
C6	YEL	Under all conditions	Check for continuity between terminal C6 and body ground: There should be no continuity.	A short to ground in the L-LINE wire
B10	GRY	Press the engine start/stop switch button	Measure the voltage to ground: There should be battery voltage.	Blown No. D30 fuse Faulty engine start/stop switch An open or high resistance in the wire
B11	BLU	Press the engine start/stop switch button	Check for continuity to ground: There should be continuity.	Faulty keyless access/TPMS control unit Faulty engine start/stop switch An open or high resistance in the wire
C5	RED	Jump the SCS line with the HDS, disconnect PCM connector A (51P)	Check for continuity between terminal C5 and PCM connector A (51P) terminal No. 38: There should be continuity.	An open in the S-NET wire PCM
		Disconnect driver's under-dash fuse/relay box connector H (13P)	Check for continuity between terminal C5 and driver's under-dash fuse/relay box connector H (13P) terminal No. 12: There should be continuity.	An open in the S-NET wire Faulty driver's under-dash fuse/relay box
			Check for continuity between terminal C5 and body ground: There should be no continuity.	A short to ground in the S-NET wire

5. 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, replace the keyless access/TPMS control unit .

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
A1	BLU	Under all conditions	Measure the voltage to ground: There should be battery voltage.	Blown No. D30 fuse An open or high resistance in the wire
B18	PNK	Under all conditions	Measure the voltage to ground: There should be battery voltage.	Blown No. C16 fuse An open or high resistance in the wire

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
A17	BRN	In all power modes	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G502) An open or high resistance in the ground wire
B36	BRN	In all power modes	Measure the voltage to ground: There should be less than 0.2 V.	Poor ground (G502) An open or high resistance in the ground wire
B30	LT GRN	Vehicle ON mode	Measure the voltage to ground: There should be battery voltage.	Blown No. B3-4 fuse Faulty under-dash subrelay box An open or high resistance in the wire
B34	GRN	Vehicle ON mode	Measure the voltage to ground: There should be battery voltage.	Blown No. C5 fuse Blown No. D12 fuse Faulty under-dash subrelay box An open or high resistance in the wire
B29	GRN	Vehicle ON mode	Measure the voltage to ground: There should be battery voltage.	Blown No. B3-6 fuse Faulty under-dash subrelay box An open or high resistance in the wire
B27	RED	Vehicle ON mode	Measure the voltage to ground: There should be battery voltage.	Blown No. B3-4 fuse Faulty under-dash subrelay box An open or high resistance in the wire
C14	BRN	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 (G502) or an open in the ground wire An open or high resistance in the wire
C14	BRN	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	RED	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 (G505) or an open in the ground wire An open or high resistance in the wire
C13	RED	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
C7	BRN	Left rear door outer handle lock button pushed	Measure the voltage to ground: There should be less than 0.2 V.	Faulty left rear door outer handle Poor ground (G701) or an open in the ground wire An open or high resistance in the wire
C7	BRN	Left rear door outer handle lock button released	Measure the voltage to ground: There should be about 5 V.	Faulty left rear door outer handle A short to ground in the wire

Cavity	Wire	Test condition	Test: Desired result	Possible cause if desired result is not obtained
C8	PUR	Right rear door outer handle lock button pushed	Measure the voltage to ground: There should be less than 0.2 V.	Faulty right rear door outer handle Poor ground (G751) or an open in the ground wire An open or high resistance in the wire
C8	PUR	Right rear door outer handle lock button released	Measure the voltage to ground: There should be about 5 V.	Faulty right rear door outer handle A short to ground in the wire
B1	LT BLU	Electric parking brake switch pulled (apply)	Measure the voltage to ground: There should be less than 0.2 V.	Faulty electric parking brake switch Faulty electric parking brake switch ground An open or high resistance in the wire
B1	LT BLU	Brake pedal pressed and electric parking brake switch pushed (released)	Measure the voltage to ground: There should be about 5 V.	Faulty electric parking brake switch A short to ground in the wire
C16	LT BLU	Trunk lid outer handle switch pushed	Measure the voltage to ground: There should be less than 0.2 V.	Faulty trunk lid outer handle switch An open or high resistance in the wire
C16	LT BLU	Trunk lid outer handle switch released	Measure the voltage to ground: There should be about 5 V.	Faulty trunk lid outer handle switch A short to ground in the wire
C10	GRN	Shift position/mode in P	Measure the voltage to ground: There should be less than 0.2 V.	Faulty TCM Poor ground (G101) or an open in the ground wire An open or high resistance in the wire
C10	GRN	Shift position/mode in any position/mode other than P	Measure the voltage to ground: There should be about 5 V.	Faulty TCM A short to ground in the wire
B19	LT GRN	Brake pedal pressed	Measure the voltage to ground: There should be battery voltage.	Blown No. C19 fuse Faulty brake pedal position switch An open or high resistance in the wire A short to ground in the wire
B19	LT GRN	Brake pedal released	Measure the voltage to ground: There should be less than 0.2 V.	Faulty brake pedal position switch