DTC Troubleshooting: P0068
DTC P0068: Throttle Position Correlation
Do not insert your fingers into the installed throttle body when you turn the vehicle to the ON mode, or while the vehicle is in ON mode. If you do, you will seriously injure your fingers if the throttle valve is activated.

NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
P0068 Throttle Position Correlation
    

1.
Throttle body condition check:

Throttle body condition check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the throttle body inlet pipe and the throttle body connector tube from the throttle body.

?3.
Check for sludge or carbon on the throttle valve.

Is there sludge or carbon on the throttle valve?

     
YES
     
     
     
     
NO
     
     
     
Go to step 2.
2.
Problem verification:

Problem verification
?1.
Reconnect the throttle body inlet pipe and the throttle body connector tube to the throttle body.

?2.
Record all the on-board snapshots with the HDS.

?3.
Turn the vehicle to the ON mode.

?4.
Clear the DTC with the HDS.


?5.
Start the engine.

?6.
Test-drive the vehicle for several minutes in the range of these recorded on-board snapshot parameters:
Engine Speed
Vehicle Speed
MAP Sensor (Hi Res)
TC Boost Pressure
Baro Sensor
REL TP Sensor
Signal
Current conditions
Values
Unit
Engine Speed
    
Vehicle Speed
    
MAP Sensor (Hi Res)
    
TC Boost Pressure
    
Baro Sensor
    
REL TP Sensor
    

?7.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P0068 Throttle Position Correlation
    

Is DTC P0068 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 3.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at MAF sensor/IAT sensor 1, MAP sensor/IAT sensor 2, the turbocharger boost sensor, and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?
3.
Sensor signal check:

Sensor signal check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Turn the vehicle to the ON mode.

?3.
Check the parameter(s) below with the HDS.
Signal
Current conditions
Values
Unit
Baro Sensor
    
TC Boost Pressure
    
MAP Sensor (Hi Res)
    

?4.
Check the difference of A: Baro Sensor and TC Boost Pressure, and B: Baro Sensor and MAP Sensor (Hi Res), then compare the results with the following table.
 
A
(Difference of Baro Sensor
and TC Boost Sensor)
B
(Difference of Baro Sensor
and MAP Sensor (Hi Res))
Pattern 1
Almost 0
Difference exists
Pattern 2
Difference exists
Almost 0
Pattern 3
Almost 0
Almost 0
Pattern 4
Difference exists
nearly the same as B
Difference exists
nearly the same as A

Which pattern do the results match?

     
Pattern 1
     
     
     
Go to step 4.
     
Pattern 2
     
     
     
Go to step 5.
     
Pattern 3
     
     
     
Go to step 4.
     
Pattern 4
     
     
     
Go to step 4.
4.
MAP sensor/IAT sensor 2 check:

MAP sensor/IAT sensor 2 check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Substitute a known-good MAP sensor/IAT sensor 2.

?3.
Reconnect all connectors.

?4.
Turn the vehicle to the ON mode.

?5.
Clear the DTC with the HDS.


?6.
Start the engine.

?7.
Test-drive the vehicle for several minutes in the range of these recorded on-board snapshot parameters:
Engine Speed
Vehicle Speed
MAP Sensor (Hi Res)
TC Boost Pressure
Baro Sensor
REL TP Sensor
Signal
Current conditions
Values
Unit
Engine Speed
    
Vehicle Speed
    
MAP Sensor (Hi Res)
    
TC Boost Pressure
    
Baro Sensor
    
REL TP Sensor
    

?8.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P0068 Throttle Position Correlation
    

Is DTC P0068 indicated?

     
YES
     
     
     
MAP sensor/IAT sensor 2 is OK. Replace the turbocharger boost sensor and recheck. If DTC P0068 is indicated again, replace the throttle body.?
     
NO
     
     
     
5.
Turbocharger boost sensor check:

Turbocharger boost sensor check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Substitute a known-good turbocharger boost sensor.

?3.
Reconnect all connectors.

?4.
Turn the vehicle to the ON mode.

?5.
Clear the DTC with the HDS.


?6.
Start the engine.

?7.
Test-drive the vehicle for several minutes in the range of these recorded on-board snapshot parameters:
Engine Speed
Vehicle Speed
MAP Sensor (Hi Res)
TC Boost Pressure
Baro Sensor
REL TP Sensor
Signal
Current conditions
Values
Unit
Engine Speed
    
Vehicle Speed
    
MAP Sensor (Hi Res)
    
TC Boost Pressure
    
Baro Sensor
    
REL TP Sensor
    

?8.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P0068 Throttle Position Correlation
    

Is DTC P0068 indicated?

     
YES
     
     
     
The turbocharger boost sensor is OK. Replace MAP sensor/IAT sensor 2 and recheck. If DTC P0068 is indicated again, replace the throttle body.?
     
NO