2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1773
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions)provides an overview of each diagnostic category.
DTC Descriptors
DTC P0068
- Throttle Body Airflow Performance
DTC P0121
- Throttle Position (TP) Sensor 1 Performance
Circuit/System Description
The engine control module (ECM) uses the following information to calculate an expected airflow rate:
* The throttle position (TP)
* The barometric pressure (BARO)
* The manifold absolute pressure (MAP)
* The intake air temperature (IAT)
* The engine RPM
Conditions for Running the DTC
P0068
* DTCs P0641, P0651, P1516, P2101, P2119, P2176 are not set.
* The engine is running.
* DTC P0068 run continuously when the above conditions are met.
P0121
* DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0315, P0335, P0336 are not set.
* The engine speed is more than 450 RPM.
* DTC P0121 run continuously when the above conditions are met.
Conditions for Setting the DTC
P0068
The ECM detects that the throttle position and the indicated engine load do not correspond with the expected load and throttle position for less than
1 second.
P0121
The predicted air flow and the predicted MAP combined are outside a calibrated range for more than 3 seconds.
Action Taken When the DTC Sets
P0068
* DTC P0068 is a Type A DTC.
* The control module commands the throttle actuator control (TAC) system to operate in the Reduced Engine Power mode.
* A message center or an indicator displays Reduced Engine Power.
* Under certain conditions the control module commands the engine OFF.
P0121
DTC P0121 is a Type B DTC.
Conditions for Clearing the MIL/DTC
* DTC P0068 is a Type A DTC.
* DTC P0121 is a Type B DTC.
