DTC P0068

DTC P0068  : Throttle Position Correlation

WARNING:  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 (PGM-FI)

1. 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 

   Clean the throttle body .

   NO 

   Go to step 2.

2. 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.

   Clear DTC

   -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

   On-board Snapshot

   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

   -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

   -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.

   Clear DTC

   -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

   On-board Snapshot

   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 

   Replace original MAP sensor/IAT sensor 2 .

5. 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.

   Clear DTC

   -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

   On-board Snapshot

   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 

   Replace the original turbocharger boost sensor .