DTC P0641

DTC P0641  : Sensor Reference Voltage A Malfunction

DTC (PGM-FI)

1. Problem verification

   -1. Turn the vehicle to the ON mode.

   -2. Clear the DTC with the HDS.

   -3. Turn the vehicle to the OFF (LOCK) mode.

   -4. Turn the vehicle to the ON mode.

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

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

   DTC (PGM-FI)

   Is DTC P0641 indicated?

   YES 

   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 .

   • CKP sensor
   • MAP sensor
   • Throttle body
   • APP sensor
2. Determine possible failure area (VCC lines, others)

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

   -2. Disconnect the following connectors.

   CKP sensor 3P connector

   MAP sensor 3P connector

   Throttle body 6P connector

   APP sensor 6P connector

   -3. Turn the vehicle to the ON mode.

   -4. Clear the DTC with the HDS.

   -5. Turn the vehicle to the OFF (LOCK) mode.

   -6. Turn the vehicle to the ON mode.

   -7. Check for Pending or Confirmed DTCs with the HDS.

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

   DTC (PGM-FI)

   Is DTC P0641 indicated?

   YES 

   Go to step 4.

   NO 

   Go to step 3.

3. Shorted part check:

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

   • CKP sensor
   • MAP sensor
   • Throttle body
   • APP sensor

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

   DTC (PGM-FI)

   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.

   • CKP sensor
   • MAP sensor
   • Throttle body
   • APP sensor
4. Shorted wire check (VCC lines)

   -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 OFF (LOCK) mode
   	CKP sensor 3P connector: disconnected
   	MAP sensor 3P connector: disconnected
   	Throttle body 6P connector: disconnected
   	APP sensor 6P connector: disconnected
   	PCM connector A (50P): disconnected
   	PCM connector E (80P): disconnected

   Connector	Terminal
   PCM connector A (50P)	No. 45
   PCM connector E (80P)	No. 70 and No. 75

   Is there continuity?

   YES 

   Repair a short in the VCC wire(s) between the PCM (A45, E70, E75) and each part that was disconnected in step 2.

   NO 

   Go to step 5.

5. Shorted wire check (VCC lines to power)

   -1. Exit the SCS mode with the HDS.

   -2. Turn the vehicle to the ON mode.

   -3. Measure the voltage between these test points and body ground individually.

   Test condition	Vehicle ON mode
   	CKP sensor 3P connector: disconnected
   	MAP sensor 3P connector: disconnected
   	Throttle body 6P connector: disconnected
   	APP sensor 6P connector: disconnected
   	PCM connector A (50P): disconnected
   	PCM connector E (80P): disconnected

   Connector	Terminal
   PCM connector A (50P)	No. 45
   PCM connector E (80P)	No. 70 and No. 75

   Is there any voltage?

   YES 

   Repair a short to power in the VCC wire(s) between the PCM (A45, E70, E75) 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 P0641 goes away and the PCM was substituted, replace the original PCM .