2010 Cadillac Truck SRX FWD V6-3.0L Page 1147
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the
conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the Q38 throttle body assembly.
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohm
between the low reference circuit terminal C and ground.
瀚慖f greater than the specified range, test the low reference circuit for a short to voltage, or an open/high resistance. If the circuit tests
normal, replace the K20 ECM.
3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal E and ground.
瀚慖f less than the specified range, test the 5 V reference circuit for a short to ground or open/high resistance. If the circuit tests normal,
replace the K20 ECM.
瀚慖f greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
4. Test for less than 1 V between the TP sensor 1 signal circuit terminal D and ground.
瀚慖f greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
5. Test for 4.8-5.2 V between the TP sensor 2 signal circuit terminal F and ground.
瀚慖f less than specified range, test the signal circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the
K20 ECM.
瀚慖f greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
6. Install a 3 A fused jumper wire between TP sensor 1 signal circuit terminal D and the 5 V reference circuit terminal E. Verify the scan tool
TP sensor 1 voltage parameter is greater than 4.8 V.
瀚慖f less than the specified range, test the signal circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace
the K20 ECM.
7. If all circuits test normal, test or replace the Q38 throttle body assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.
* Throttle Body Assembly Replacement (LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Throttle Body/Service and
Repair/Removal and Replacement)Throttle Body Assembly Replacement (LAU) (See: Powertrain Management/Fuel Delivery and Air
Induction/Throttle Body/Service and Repair/Removal and Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, programming, and setup
P0122
DTC P0121-P0123, P0222, P0223, or P2135 (LF1, LFW)
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 P0121
- Throttle Position Sensor Performance
DTC P0122
- Throttle Position Sensor 1 Circuit Low Voltage
DTC P0123
- Throttle Position Sensor 1 Circuit High Voltage
