D4 Switch Circuit Troubleshooting

D4 Switch Circuit Troubleshooting 

1. D4 switch check

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

   - 2. Disconnect the following connector.

   D4 switch 2P connector

   - 3. Test the D4 switch.

   Does the D4 switch test OK?

   YES 

   The D4 switch is OK. Go to step 2.

   NO 

   Replace the D4 switch .

2. Problem verification

   - 1. Turn the vehicle to the ON mode.

   - 2. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	D4 switch 2P connector: disconnected
   Test point 1	D4 switch 2P connector No. 1
   Test point 2	D4 switch 2P connector No. 2

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

   Is there battery voltage?

   YES 

   Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good PCM - Refer to: PCM Removal and Installation (2019 2020 2021) or PCM Removal and Installation (2016 2017 2018) .

   NO 

   Go to step 3.

3. Open wire check (GND line)

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

   - 2. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	D4 switch 2P connector: disconnected
   Test point 1	D4 switch 2P connector No. 1
   Test point 2	Body ground

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

   Is there continuity?

   YES 

   The GND wire is OK. Go to step 4.

   NO 

   Repair an open in the GND wire between the D4 switch 2P connector and ground (G405), or repair poor ground (G405).

4. Shorted wire check (D4 SW line)

   - 1. Jump the SCS line with the HDS, and wait more than 1 minute.

   - 2. Disconnect the following connector.

   PCM connector A (51P)

   - 3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	D4 switch 2P connector: disconnected
   	PCM connector A (51P): disconnected
   Test point 1	D4 switch 2P connector No. 2
   Test point 2	Body ground

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

   Is there continuity?

   YES 

   Repair a short to ground in the D4 SW wire between the D4 switch 2P connector and the PCM.

   NO 

   The D4 SW wire is not shorted. Go to step 5.

5. Open wire check (D4 SW line)

   - 1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	D4 switch 2P connector: disconnected
   	PCM connector A (51P): disconnected
   Test point 1	D4 switch 2P connector No. 2
   Test point 2	PCM connector A (51P) No. 34 - Refer to: PCM Connector for Inputs and Outputs (2016 2017 2018) (9-Speed A/T) or PCM Connector for Inputs and Outputs (2019 2020 2021) (9-Speed A/T) or PCM Connector for Inputs and Outputs (2016 2017 2018 2019 2020) (6-Speed A/T)

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

   Is there continuity?

   YES 

   The D4 SW wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good PCM - Refer to: PCM Removal and Installation (2019 2020 2021) or PCM Removal and Installation (2016 2017 2018) .

   NO 

   Repair an open in the D4 SW wire between the D4 switch 2P connector and the PCM.