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
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
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 on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?
CMP sensor A
CMP sensor B
Turbocharger boost sensor
Turbocharger
MAF sensor/IAT sensor 1
APP sensor
A/C pressure sensor
FTP sensor
Neutral position sensor
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.
CMP sensor A 3P connector
CMP sensor B 3P connector
Turbocharger boost sensor 3P connector
Turbocharger 5P connector
MAF sensor/IAT sensor 1 4P connector
APP sensor 6P connector
A/C pressure sensor 3P connector
FTP sensor 3P connector
Neutral position sensor 4P connector

?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
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:
CMP sensor A
CMP sensor B
Turbocharger boost sensor
Turbocharger
MAF sensor/IAT sensor 1
APP sensor
A/C pressure sensor
FTP sensor
Neutral position sensor

DTC Description
Confirmed DTC
Pending DTC
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.
CMP sensor A
CMP sensor B
Turbocharger boost sensor
Turbocharger
MAF sensor/IAT sensor 1
APP sensor
A/C pressure sensor
FTP sensor
Neutral position sensor
4.
Shorted wire check (VCC lines to ground):

Shorted wire check (VCC lines to ground)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
Disconnect the following connectors.
PCM connector A (50P)
PCM connector E (80P)

?4.
Check for continuity between these test points and body ground individually.
Test condition
Vehicle ON mode
 
CMP sensor A 3P connector: disconnected
 
CMP sensor B 3P connector: disconnected
 
Turbocharger boost sensor 3P connector: disconnected
 
Turbocharger 5P connector: disconnected
 
MAF sensor/IAT sensor 1 4P connector: disconnected
 
APP sensor 6P connector: disconnected
 
A/C pressure sensor 3P connector: disconnected
 
FTP sensor 3P connector: disconnected
 
Neutral position sensor 4P connector: disconnected
 
PCM connector A (50P): disconnected
 
PCM connector E (80P): disconnected

Connector
Terminal
PCM connector A (50P)
No. 44
PCM connector E (80P)
No. 63 and No. 77

Is there continuity?

     
YES
     
     
     
Repair a short to ground in the VCC wire between the PCM (A44, E63, E77) and each part that was disconnected in step 2.?
     
NO
     
     
     
Go to step 5.
5.
Shorted wire check (VCC lines to power):

Shorted wire check (VCC lines to power)
?1.
Turn the vehicle to the ON mode.

?2.
Measure the voltage between these test points and body ground individually.
Test condition
Vehicle ON mode
 
CMP sensor A 3P connector: disconnected
 
CMP sensor B 3P connector: disconnected
 
Turbocharger boost sensor 3P connector: disconnected
 
Turbocharger 5P connector: disconnected
 
MAF sensor/IAT sensor 1 4P connector: disconnected
 
APP sensor 6P connector: disconnected
 
A/C pressure sensor 3P connector: disconnected
 
FTP sensor 3P connector: disconnected
 
Neutral position sensor 4P connector: disconnected
 
PCM connector A (50P): disconnected
 
PCM connector E (80P): disconnected

Connector
Terminal
PCM connector A (50P)
No. 44
PCM connector E (80P)
No. 63 and No. 77

Is there any voltage?

     
YES
     
     
     
Repair a short to power in the VCC wire between the PCM (A44, E63, E77) and each part that was disconnected in step 2.?
     
NO
     
     
     
The VCC wires are OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P0651 goes away and the PCM was substituted, replace the original PCM.?