P 0068 code?
#6
TECH Senior Member
iTrader: (5)
Originally Posted by smask04C5
I replaced my stock ls6 intake and tb for a fast/NW 90, and it set this code twice in 10 miles. I reset with crane hh and looked on gearchatter for source. Can anyone explain in laymans terms what is going on? Thanks
DTC P0068
Circuit Description
The powertrain control module (PCM) uses the throttle position (TP), barometric pressure (BARO), intake air temperature (IAT), and engine RPM in order to calculate the predicted mass airflow rate. The PCM compares the predicted mass air flow (MAF) value to the actual mass airflow value and the speed density calculation in order to verify the proper throttle operation. If the PCM detects that the difference between the actual air flow (MAF) and the speed density calculated air flow is greater than expected, DTC P0068 sets.
Conditions for Setting the DTC
The PCM detects that the difference between the actual airflow (MAF) and the speed density calculated airflow is greater than expected.
The above condition is met for less than 1 second.
Diagnostic Aids
Inspect the throttle blade for being broken, bent, or missing.
Inspect the TP sensor for proper installation. A sensor that is mis-aligned could set this DTC.
Inspect the TAC module connectors for signs of water intrusion. When water intrusion occurs, multiple DTCs could be set with no DTC circuit or component conditions found during diagnostic testing.
Physically and visually inspect the throttle body assembly, and correct any problems that you observe. Manually move the throttle blade from closed to wide open throttle (WOT). You should not need to use excessive force. The throttle blade should move smoothly through the full range and should return to a slightly open position on its own.
When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests that run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Keep this in mind when reviewing the stored information, Capture info.
For an intermittent condition, refer to Intermittent Conditions .
Maybe something isn't plugged in?
Inspect the throttle body for the following conditions:
A loose or damaged throttle position (TP) sensor
A loose or damaged throttle blade
A cracked or bent throttle shaft
Drive mechanism damage
Did you find and correct the condition?
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#8
TECH Senior Member
iTrader: (5)
Originally Posted by smask04C5
Thank you, V series tech for the info. I will reinspect the install this evening, to include checking the tp sensor. Manually moved the throttle blade with and without the stepper motor installed, no binding throughout movement.
No problem,...let us know what happens.
j