DTC P0641 (2014 2015 2016 PGM-FI System (Without Auto Idle Stop System))

DTC P0641 : Sensor Reference Voltage A Malfunction

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
P0641 Sensor Reference Voltage A Malfunction

DTC (PGM-FI)

Problem verification

-1. Turn the vehicle to the ON mode.

- 2. Clear the DTC with the HDS.

- 3. Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P0641 Sensor Reference Voltage A Malfunction

Is DTC P0641 indicated?

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 PCM and these parts, 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:?

MAP sensor
EGR valve
Fuel rail pressure sensor
APP sensor
Output shaft (countershaft) speed sensor
FTP sensor (USA models)

Determine possible failure area (VCC lines, others)

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

- 2. Disconnect the following connectors.

MAP sensor 3P connector

EGR valve 5P connector

Fuel rail pressure sensor 3P connector

APP sensor 6P connector

Output shaft (countershaft) speed sensor 3P connector

FTP sensor 3P connector (USA models)

- 3. Turn the vehicle to the ON mode.

- 4. Clear the DTC with the HDS.

- 5. Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P0641 Sensor Reference Voltage A Malfunction

Is DTC P0641 indicated?

YES

Go to step 4.

Go to step 3.

Shorted part check

-1. Check for Pending or Confirmed DTCs with the HDS while reconnecting these parts, one at a time:

MAP sensor
EGR valve
Fuel rail pressure sensor
APP sensor
Output shaft (countershaft) speed sensor
FTP sensor (USA models)

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P0641 Sensor Reference Voltage A Malfunction

Is DTC P0641 indicated?

YES

Replace the part that caused the DTC when it was reconnected.

Check for poor connections or loose terminals at the PCM and the following parts, then go to step 1.

MAP sensor
EGR valve
Fuel rail pressure sensor
APP sensor
Output shaft (countershaft) speed sensor
FTP sensor (USA models)

Shorted wire check (VCC lines to power)

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

- 2. Jump the SCS line with the HDS.

- 3. Disconnect the following connectors.

PCM connector A (51P) - Refer to: 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), or How to Troubleshoot the A/T System (2014 2015), or How to Troubleshoot the Fuel and Emissions Systems

PCM connector C (51P) - Refer to: 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), or How to Troubleshoot the A/T System (2014 2015)

- 4. Turn the vehicle to the ON mode.

- 5. Measure the voltage between these test points and body ground individually.

Test condition	Vehicle ON mode
	MAP sensor 3P connector: disconnected
	EGR valve 5P connector: disconnected
	Fuel rail pressure sensor 3P connector: disconnected
	APP sensor 6P connector: disconnected
	Output shaft (countershaft) speed sensor 3P connector: disconnected
	FTP sensor 3P connector (USA models): disconnected
	PCM connector A (51P): disconnected
	PCM connector C (51P): disconnected

Connector	Test circuit	Terminal
PCM connector C (51P)	VCC1	No. 32 (PNK)
PCM connector A (51P)	VCC3	No. 41 (RED)

PCM connector A (51P)

VCC7

No. 19 (ORN)

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

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

Is there about 5.2V or more?

YES

Repair a short to power in the VCC wire between the PCM (A19, A41, or C32) and each part that was disconnected in step 2.

Go to step 5.

Shorted wire check (VCC lines)

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

- 2. Check for continuity between these test points and body ground individually.

Test condition	Vehicle OFF (LOCK) mode
	MAP sensor 3P connector: disconnected
	EGR valve 5P connector: disconnected
	Fuel rail pressure sensor 3P connector: disconnected
	APP sensor 6P connector: disconnected
	Output shaft (countershaft) speed sensor 3P connector: disconnected
	FTP sensor 3P connector (USA models): disconnected
	PCM connector A (51P): disconnected
	PCM connector C (51P): disconnected

Connector	Test circuit	Terminal
PCM connector C (51P)	VCC1	No. 32 (PNK)
PCM connector A (51P)	VCC3	No. 41 (RED)
PCM connector A (51P)	VCC7	No. 19 (ORN)

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

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

Is there continuity?

YES

Repair a short in the VCC wire between the PCM (A19, A41, or C32) and each part that was disconnected in step 2.

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) .