DTC Troubleshooting: P0641
DTC P0641: Sensor Reference Voltage A Malfunction
NOTE: Before you troubleshoot, review the general troubleshooting information.

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

Is DTC P0641 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.?
MAP sensor
Fuel rail pressure sensor
CVT drive pulley speed sensor
APP sensor
A/C pressure sensor
FTP sensor (USA 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.
MAP sensor 3P connector
Fuel rail pressure sensor 3P connector
CVT drive pulley speed sensor 3P connector
APP sensor 6P connector
A/C pressure 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
P0641 Sensor Reference Voltage A Malfunction
    

Is DTC P0641 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:
MAP sensor
Fuel rail pressure sensor
CVT drive pulley speed sensor
APP sensor
A/C pressure sensor
FTP sensor (USA models)

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

Is DTC P0641 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.
MAP sensor
Fuel rail pressure sensor
CVT drive pulley speed sensor
APP sensor
A/C pressure sensor
FTP sensor (USA models)
4.
Shorted wire check (VCC lines to power):

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

?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
Fuel rail pressure sensor 3P connector: disconnected
CVT drive pulley speed sensor 3P connector: disconnected
APP sensor 6P connector: disconnected
A/C pressure sensor 3P connector: disconnected
FTP sensor 3P connector: disconnected (USA models)
PCM connector A (51P): disconnected
PCM connector C (51P): disconnected

Connector
Terminal
PCM connector A (51P)
No. 29 and No. 31
PCM connector C (51P)
No. 41

Is there any voltage?

     
YES
     
     
     
Repair a short to power in the VCC wire between the PCM (A29, A31, or C41) and each part that was disconnected in step 2.?
     
NO
     
     
     
Go to step 5.
5.
Shorted wire check (VCC lines to ground):

Shorted wire check (VCC lines to ground)
?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
Fuel rail pressure sensor 3P connector: disconnected
CVT drive pulley speed sensor 3P connector: disconnected
APP sensor 6P connector: disconnected
A/C pressure sensor 3P connector: disconnected
FTP sensor 3P connector: disconnected (USA models)
PCM connector A (51P): disconnected
PCM connector C (51P): disconnected

Connector
Terminal
PCM connector A (51P)
No. 29 and No. 31
PCM connector C (51P)
No. 41

Is there continuity?

     
YES
     
     
     
Repair a short in the VCC wire between the PCM (A29, A31, or C41) 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.?