P2135
DTC P0121-P0123, P0222, P0223, or P2135 (LUW)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0121
- Throttle Position Sensor 1 Performance
DTC P0122
- Throttle Position Sensor 1 Circuit Low Voltage
DTC P0123
- Throttle Position Sensor 1 Circuit High Voltage
DTC P0222
- Throttle Position Sensor 2 Circuit Low Voltage
DTC P0223
- Throttle Position Sensor 2 Circuit High Voltage
DTC P2135
- Throttle Position Sensors 1-2 Not Plausible
Diagnostic Fault Information
Circuit/System Description
The throttle body assembly contains 2 throttle position sensors. The throttle position sensors are mounted to the throttle body assembly and are not serviceable. The throttle position sensors provide a signal voltage that changes relative to throttle blade angle. The engine control module ECM) supplies the throttle position sensors with a common 5 V reference circuit , a common low reference circuit, and two independent signal circuits.
The throttle position sensors have opposite functionality. Throttle position sensor 1 signal voltage decreases and throttle position sensor 2 signal voltage increases as the accelerator pedal increases to wide open throttle (WOT).
Conditions for Running the DTC
P0121
* DTCs P0102, P0103, P0107, P0111, P0112, P0113, P0116, P0117, P0118, P0119, P0335 or P0336 are not set.
* The engine speed is between 400-7 000 RPM.
* The engine coolant temperature (ECT) is between -7 to +125°C (19.4 to +257°F).
* The intake air temperature (IAT) is between -20 to +125°C (19.4 to +257°F).
* The DTC runs continuously when the above conditions are met.
P0122, P0123, P0222, P0223
* DTC P06A3 is not set.
* The system voltage is more than 6.41 V.
* The ignition is ON, or the engine is running.
* The engine is not operating in reduced power mode.
* These DTCs run continuously when the above conditions are met.
P2135
* DTCs P0122, P0123, P0222, P0223, or P06A3 are not set.
* The ignition voltage is greater than 6.41 V.
* The ignition is ON, or the engine is running.
* The engine is not operating in reduced power mode.
* The DTC runs continuously when the above conditions are met.
Conditions for Setting the DTC
P0121
The engine control module determines if the throttle position sensor input is stuck within the normal operating range.
P0122
The engine control module detects that the throttle position sensor 1 voltage is less than 0.32 V.
P0123
The engine control module detects that the throttle position sensor 1 voltage is greater than 4.75 V.
P0222
The engine control module detects that the throttle position sensor 2 voltage is less than 0.25 V.
P0223
The engine control module detects that the throttle position sensor 2 voltage is greater than 4.59 V.
P2135
The correlation difference between throttle position sensor 1 and throttle position sensor 2 exceeds calibrated limits.
Action Taken When the DTC Sets
* DTC P0121 is a Type B DTC.
* DTCs P0122, P0123, P0222, P0223, and P2135 are Type A DTCs.
* The control module commands the throttle actuator control (TAC) system to operate in the Reduced Engine Power mode.
* Under certain conditions the control module commands the engine OFF.
Conditions for Clearing the DTC
* DTC P0121 is a Type B DTC.
* DTCs P0122, P0123, P0222, P0223, and P2135 are Type A DTCs.
Diagnostic Aids
* It may be necessary to disconnect the battery to clear DTC P2135.
* A high resistance condition on the throttle position and throttle actuator control circuits could cause a DTC to set.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Throttle Actuator Control (TAC) System Description Throttle Actuator Control (TAC) System Description
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P06A3 is not set.
• If DTC P06A3 is set, refer to DTC P0641, P0651, P0697, or P06A3 (LUW, ECM) Powertrain Management (LUW, ECM) for further diagnosis.
2. Ignition ON, observe both Throttle Position Sensor 1 and 2 voltage parameters with a scan tool. Verify the scan tool Throttle Position Sensor 1 and 2 parameters are between 0.50-4.5 V and change with accelerator pedal input.
3. Perform the Throttle Sweep Test while observing the Throttle Position Sensor 1 and 2 Agree/Disagree parameters with a scan tool. The Throttle Position Sensor 1 and 2 Agree/Disagree parameters should display Agree.
4. Observe the DTC Information with a scan tool. DTCs P0121, P0122, P0123, P0221, P0222, and P0223 should not be set.
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
Note: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
1. Ignition OFF, all vehicles systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Disconnect the harness connector at the Q38 Throttle Body.
2. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal C and ground.
• If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal E and ground.
• If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
4. Test for less than 1 V between the Throttle Position Sensor 1 signal circuit terminal D and ground.
• If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
5. Test for 4.8-5.2 V between the Throttle Position Sensor 2 signal circuit terminal F and ground.
• If 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 Engine Control Module.
• If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
6. Install a 3 A fused jumper wire between Throttle Position Sensor 1 signal circuit terminal D and the 5 V reference circuit terminal E. Verify the scan tool Throttle Position Sensor 1 voltage parameter is greater than 4.8 V.
• If 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 Engine Control Module.
7. If all circuits test normal, replace the Q38 Throttle Body.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Throttle Body Assembly Replacement Removal and Replacement
* Control Module References Control Module References for ECM replacement, programming, and setup.