DTC P2127

DTC P2127 : APP Sensor B (TP Sensor E) Circuit Low Voltage

NOTE: Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems, or How to Troubleshoot the A/T System (2014 2015), or How to Troubleshoot the Brake Booster Pressure Monitoring System (2016 2017 2018 2019 2020), or How to Troubleshoot the Fuel and Emissions Systems(With Auto Idle Stop System) (2016) .

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P2127 APP Sensor B (TP Sensor E) Circuit Low Voltage

DTC (PGM-FI)

Problem verification

-1. Turn the vehicle to the ON mode.

- 2. Check the parameter(s) below with the HDS.

Signal	Threshold		Current conditions
Signal	Values	Unit	Values	Unit
APP SENSOR B	Less than 0.2	V

Do the current condition(s) match the threshold?

YES

The failure is duplicated. Go to step 2.

Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the APP sensor and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.

Determine possible failure area (VCC4 line, others)

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

- 2. Disconnect the following connector.

APP sensor 6P connector

- 3. Turn the vehicle to the ON mode.

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

Test condition	Vehicle ON mode
	APP sensor 6P connector: disconnected
Test circuit	VCC4, SG4
Test point 1	APP sensor 6P connector No. 1 (LT BLU)
Test point 2	APP sensor 6P connector No. 2 (BLK)

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

Is there about 5.0 V?

YES

Go to step 3.

Go to step 6.

Shorted wire check (AP2 line)

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

- 2. Jump the SCS line with the HDS.

- 3. Disconnect the following connector.

PCM connector A (51P) - Refer to: How to Troubleshoot the A/T System (2014 2015), or How to Troubleshoot the Fuel and Emissions Systems, or How to Troubleshoot the Brake Booster Pressure Monitoring System (2016 2017 2018 2019 2020), or How to Troubleshoot the Fuel and Emissions Systems(With Auto Idle Stop System) (2016)

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

Test condition	Vehicle OFF (LOCK) mode
	APP sensor 6P connector: disconnected
	PCM connector A (51P): disconnected
Test circuit	AP2
Test point 1	APP sensor 6P connector No. 3 (PNK)

Test point 2

Body ground

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

Is there continuity?

YES

Repair a short in the AP2 wire between the PCM (A46) and the APP sensor.

The AP2 wire is not shorted. Go to step 4.

Open wire check (AP2 line)

-1. Connect terminals A and B with a jumper wire.

Terminal A	APP sensor 6P connector No. 3 (PNK)
Terminal B	Body ground

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

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

Test condition	Vehicle OFF (LOCK) mode
	APP sensor 6P connector: disconnected
	APP sensor 6P connector No. 3: jumped to body ground
	PCM connector A (51P): disconnected
Test circuit	AP2
Test point 1	PCM connector A (51P) No. 46 (PNK)
Test point 2	Body ground

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

Is there continuity?

YES

The AP2 wire is OK. Go to step 5.

Repair an open in the AP2 wire between the PCM (A46) and the APP sensor.

PCM internal circuit check

-1. Reconnect the following connector.

PCM connector A (51P) - Refer to: How to Troubleshoot the Fuel and Emissions Systems, or How to Troubleshoot the A/T System (2014 2015), or How to Troubleshoot the Brake Booster Pressure Monitoring System (2016 2017 2018 2019 2020), or How to Troubleshoot the Fuel and Emissions Systems(With Auto Idle Stop System) (2016)

- 2. Remove the jumper wire from the APP sensor 6P connector.

- 3. Connect terminals A and B with a jumper wire.

Terminal A	APP sensor 6P connector No. 1 (LT BLU)
Terminal B	APP sensor 6P connector No. 3 (PNK)

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

- 4. Turn the vehicle to the ON mode.

- 5. Check the parameter(s) below with the HDS.

Signal	Threshold		Current conditions
Signal	Values	Unit	Values	Unit
APP SENSOR B	Less than 0.2	V

Do the current condition(s) match the threshold?

YES

Update the PCM if it does not have the latest software, or substitute a known-good PCM - Refer to: PCM Removal and Installation (2016), or PCM Removal and Installation (2014 2015) .

Replace the APP sensor .

Open wire check (VCC4 line)

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

- 2. Jump the SCS line with the HDS.

- 3. Disconnect the following connector.

- 4. Connect terminals A and B with a jumper wire.

Terminal A	APP sensor 6P connector No. 1 (LT BLU)
Terminal B	Body ground

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

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

Test condition	Vehicle OFF (LOCK) mode
	APP sensor 6P connector: disconnected
	APP sensor 6P connector No. 1: jumped to body ground
	PCM connector A (51P): disconnected
Test circuit	VCC4
Test point 1	PCM connector A (51P) No. 42 (LT BLU)
Test point 2	Body ground

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

Is there continuity?

YES

The VCC4 wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM - Refer to: PCM Removal and Installation (2014 2015), or PCM Removal and Installation (2016) .

Repair an open in the VCC4 wire between the PCM (A42) and the APP sensor.