Keyless Access System (Keyless Access Control Unit, Electric Steering Lock, And TPMS Control Unit) (2016 2017 2018)

2020 Honda Pilot LX, FWDSECTION Keyless Access System (Keyless Access Control Unit, Electric Steering Lock, And TPMS Control Unit) (2016 2017 2018)

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 A - Initial Communication and DTC Checks .

  • Before testing, make sure the No. A6 (10 A), No. A25 (20 A)*, and the No. A26 (10 A) fuses in the under-hood fuse/relay box are OK.
  • Before testing, make sure the No. B1-3 (60 A), No. B1-5 (30 A), No. 1-6 (30 A) and the No. B10 (10 A) fuses in the auxiliary under-hood fuse/relay box are OK.
  • Before testing, make sure the No. C3 (7.5 A) fuse in the under-dash fuse/relay box is OK.
  • Some models have the rear outer handle touch sensor. Perform the troubleshooting flow where applicable.

*: Without auto idle stop system

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.

GHH312237Courtesy 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, 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 K-LINE wire
Check for continuity between terminal C4 and body ground:
 
There should be no continuity.
A short to ground in the K-LINE wire
C6 ORN 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
Check for continuity between terminal C6 and body ground:
 
There should be no continuity.
A short to ground in the L-LINE wire
B10 BLK Press the engine start/stop switch button Measure the voltage to ground:
 
There should be battery voltage.
  • Blown No. C3 (7.5 A) fuse in the under-dash fuse/relay box
  • Faulty under-dash fuse/relay box
  • Faulty engine start/stop switch
  • An open or high resistance in the wire
B11 BRN 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 LT GRN Jump the SCS line with the HDS, disconnect PCM connector A (51P) Check for continuity between terminal under-dash fuse/relay box connector F (18P) terminal No. 17 and PCM connector A (51P) terminal No. 38:
 
There should be continuity.
  • An open in the S-NET 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 in the S-NET wire
  • Faulty 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, 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.
  • Blown No. C3 (7.5 A) fuse in the under-dash fuse/relay box
  • Blown No. B1-3 (60 A) fuse in the auxiliary under-hood fuse/relay box
  • Faulty under-dash fuse/relay box
  • An open or high resistance in the wire
B18 WHT Under all conditions Measure the voltage to ground:
 
There should be battery voltage.
  • Blown No. A26 (10 A) fuse in the under-hood fuse/relay box
  • Faulty under-hood fuse/relay box
  • 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 (G405)
  • An open or high resistance in the ground wire
B36 BLK In all power modes Measure the voltage to ground:
 
There should be less than 0.2 V.
  • Poor ground (G405)
  • An open or high resistance in the ground wire
B30 YEL Vehicle ON mode Measure the voltage to ground:
 
There should be battery voltage.
  • Blown No. C24 (7.5 A) fuse in the under-dash fuse box
  • Blown No. B1-5 (30 A) fuse in the auxiliary under-hood fuse/relay box
  • Faulty under-dash fuse/relay box
  • 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.
  • Blown No. B1-5 (30 A) fuse in the auxiliary under-hood fuse/relay box
  • Blown No. C9 (7.5 A) fuse in the under-dash fuse/relay box
  • Faulty under-dash fuse/relay box
  • 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.
  • Blown No. B1-6 (30 A) fuse in the auxiliary under-hood fuse/relay box
  • Blown No. C39 (7.5 A) fuse in the under-dash fuse/relay box
  • Faulty under-dash fuse/relay box
  • 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.
  • Blown No. B10 (10 A) fuse in the auxiliary under-hood fuse/relay box
  • Faulty under-dash fuse/relay box
  • An open or high resistance in the wire
C14*4 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 (G401) or an open in the ground wire
  • An open or high resistance in the wire
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*4 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 (G405) or an open in the ground wire
  • An open or high resistance in the wire
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
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 Tailgate outer handle switch pushed Measure the voltage to ground:
 
There should be less than 0.2 V.
  • Faulty tailgate outer handle switch
  • Faulty power tailgate control unit*5
  • Poor ground (G604) or an open in the ground wire*6
  • An open or high resistance in the wire
Tailgate outer handle switch released Measure the voltage to ground:
 
There should be about 5 V.
  • Faulty tailgate outer handle switch
  • A short to ground in the wire
C10 BLU Shift lever in P position Measure the voltage to ground:
 
There should be less than 0.2 V.
  • Faulty transmission range switch*1, TCM *2
  • Poor ground (G101) or an open in the ground wire
  • An open or high resistance in the wire
Shift lever in any position other than P Measure the voltage to ground:
 
There should be about 5 V.
  • Faulty transmission range switch*1, TCM*2
  • A short to ground in the wire
C9*1 GRN Shift lever in P position Measure the voltage to ground:
 
There should be about 5 V.
  • Faulty park pin switch
  • A short to ground in the wire
Shift lever in any position other than P Measure the voltage to ground
 
:There should be less than 0.2 V.
  • Faulty park pin switch
  • Poor ground (G405) or an open in the ground wire
  • An open or high resistance in the wire
B3*3 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
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

*1: 6-speed A/T

*2: 9-speed A/T

*3: With electric steering lock

*4: With keyless access function

*5: With keyless access function and with power tailgate

*6: With keyless access function and without power tailgate

Electric Steering Lock 

NOTE: 

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

7. Disconnect the electric steering lock 12P connector.

GHH312238Courtesy of HONDA, U.S.A., INC.

8. 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.

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.
  • Blown No. C3 (7.5 A) fuse in the under-dash fuse/relay box
  • Faulty under-dash fuse/relay box
  • An open or high resistance in the wire
12 TAN Vehicle ON mode Measure the voltage to ground:
 
There should be battery voltage.
  • Blown No. C9 (7.5 A) fuse in the under-dash fuse/relay box
  • Faulty under-dash fuse/relay box
  • 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 (G401)
  • 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
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, replace the Keyless Access/TPMS Control Unit - Removal and Installation . If input failures are related to a particular control unit, replace the control unit.

RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.