DTC Troubleshooting: P0651
DTC P0651: Sensor Reference Voltage B Malfunction
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0651 Sensor Reference Voltage B Malfunction
      

1.
Problem verification:

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
P0651 Sensor Reference Voltage B Malfunction
      

Is DTC P0651 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
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.?
EGR valve
Rocker arm oil pressure sensor
CVT driven pulley speed sensor (CVT model)
CVT speed sensor (CVT model)
Torque converter turbine speed sensor (CVT model)
Throttle body
APP sensor
A/C pressure sensor (with A/C)
FTP sensor (USA and Canada models)
2.
Determine possible failure area (VCC lines, others):

Determine possible failure area (VCC lines, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connectors.
EGR valve 5P connector
Rocker arm oil pressure sensor 3P connector
CVT driven pulley speed sensor 3P connector (CVT model)
CVT speed sensor 3P connector (CVT model)
Torque converter turbine speed sensor 3P connector (CVT model)
Throttle body 6P connector
APP sensor 6P connector
A/C pressure sensor 3P connector (with A/C)
FTP sensor 3P connector (USA and Canada 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
P0651 Sensor Reference Voltage B Malfunction
      

Is DTC P0651 indicated?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
Go to step 3.
3.
Shorted part check:

Shorted part check
?1.
Check for Pending or Confirmed DTCs with the HDS while reconnecting these parts, one at a time:
EGR valve
Rocker arm oil pressure sensor
CVT driven pulley speed sensor (CVT model)
CVT speed sensor (CVT model)
Torque converter turbine speed sensor (CVT model)
Throttle body
APP sensor
A/C pressure sensor (with A/C)
FTP sensor (USA and Canada models)

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0651 Sensor Reference Voltage B Malfunction
      

Is DTC P0651 indicated?

     
YES
     
     
     
Replace the part that caused the DTC when it was reconnected.?
     
NO
     
     
     
Check for poor connections or loose terminals at the PCM and the following parts, then go to step 1.
EGR valve
Rocker arm oil pressure sensor
CVT driven pulley speed sensor (CVT model)
CVT speed sensor (CVT model)
Torque converter turbine speed sensor (CVT model)
Throttle body
APP sensor
A/C pressure sensor (with A/C)
FTP sensor (USA and Canada models)
4.
Shorted wire check (VCC lines):

Shorted wire check (VCC lines)
?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)
PCM connector B (51P)
PCM connector C (51P)

?4.
Check for continuity between these test points and body ground individually.
Test condition
Vehicle OFF (LOCK) mode
EGR valve 5P connector: disconnected
Rocker arm oil pressure sensor 3P connector: disconnected
CVT driven pulley speed sensor 3P connector: disconnected (CVT model)
CVT speed sensor 3P connector: disconnected (CVT model)
Torque converter turbine speed sensor 3P connector: disconnected (CVT model)
Throttle body 6P connector: disconnected
APP sensor 6P connector: disconnected
A/C pressure sensor 3P connector: disconnected (with A/C)
FTP sensor 3P connector: disconnected (USA and Canada models)
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
PCM connector C (51P): disconnected

Connector
Terminal
PCM connector A (51P)
No. 40
PCM connector B (51P)
No. 48
PCM connector C (51P)
No. 30

Is there continuity?

     
YES
     
     
     
Repair a short in the VCC wire between the PCM (A40, B48, or C30) and each part that was disconnected in step 2.?
     
NO
     
     
     
The VCC wires are OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P0651 goes away and the PCM was updated, troubleshooting is complete. If DTC P0651 goes away and the PCM was substituted, replace the original PCM.?