DTC P02E0, P02E3, P02EB, P122B, P122C, P1425, or P2957

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5903613 DTC P02E0, P02E3, P02EB, P122B, P122C, P1425, or P2957 Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions DTC Descriptor DTC P02E0 Intake Air Flow Valve Control Circuit DTC P02E3 Intake Air Flow Control Valve Control Circuit High DTC P02EB Intake Air Flow Control Valve Current Performance DTC P122B Intake Air Flow Control Valve Control Supply Voltage Circuit DTC P122C Intake Air Flow Control Valve Control Circuit Shorted DTC P1425 Intake Air Flow Control Valve Driver Temperature Too High DTC P2957 Cold Start Intake Air Flow Control Valve Current Performance Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performanc
Control — Terminal 1	P122C	P02E0	P122C, P122D	P02E1, P1425
Control — Terminal 2	P122C	P02E0	P122C, P122D	P02E1, P1425

Circuit/System Description For an overview of the component/system, refer to: Intake Airflow Valve System Description

	Circuit	Description
	Control — Terminal 1	The output circuit is switched from ground to 12 V to activate the component. The output is PWM controlled.
	Control — Terminal 2	The output circuit is switched from ground to 12 V to activate the component. The output is PWM controlled.

Component	Description
K20 Engine Control Module	The control module contains a microprocessor used to process input data to control outputs. The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly.
Q20 Intake Airflow Control Valve	The assembly has several functions: The valve is actuated by a 12 V DC motor. A spring is used to keep the valve in the open position. The valve actuator motor moves the valve in the closed direction. The more current flows through the motor, the more the valve closes. The component contains a contactless inductive position sensor. A fixed transmitter coil excites a movable rotor, which in turn induces a current in a fixed receiver coil. The current varies with the angle of the rotor. Electronics inside the sensor convert the current into digital data which is transmitted via a serial data circuit to the control module.

Conditions for Running the DTC DTC P02E8, P02E9, P0651 = Not set M64 Starter = Not Activated { P2957 } Q20 Intake Airflow Control Valve = Closed { P02E0 } Q20 Intake Airflow Control Valve = Off { P02E3, P02EB, P122C } Q20 Intake Airflow Control Valve = On Ignition and Start Switch Signal = On or Engine = Running Ignition and Start Signal = Greater than 11 V Frequency the DTC runs = Continuously — After the running conditions are met — For greater than 2 s Conditions for Setting the DTC P02E0 Control Circuit = The control module detects an open circuit. — For greater than 1 s P02E3 Control Circuit = Greater than 9 A — For greater than 3 s P02EB Control Circuit = Greater than 5.5 A — For greater than 1 s P122B Control Circuit System Voltage Out of Range = Less than 6 V — For greater than 1 s P122C Control circuit terminal 1 & 2 = Short between the circuits — For greater than 1 s P1425 Control module K20 detects: = High Current — For greater than 1 s P2957 Intake Air Flow Valve Position ≠ Desired Intake Air Flow Valve Position Greater than 10% — For greater than 8 s Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type A DTC Reduced Engine Power = Active Warning Message = Reduced Engine Power Warning Message = Service Emission System / Service Exhaust Fluid System Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type A DTC Diagnostic Aids A high resistance condition on the component circuits may cause the DTC to set. A weak battery may cause this DTC to set. Reference Information Schematic Reference Engine Controls Schematics Connector End View Reference Master Electrical Component List Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions Scan Tool Reference Control Module References Circuit/System Verification

1. Engine » Idling
2. Perform the scan tool control function: Intake Air Flow Control Valve Position » Command the component to the maximum position/speed & Minimum position/speed
3. Perform the action while monitoring the parameter: Intake Air Flow Control Valve Control Circuit High Test Status = Not Run or Okay Intake Air Flow Control Valve Control Circuit Low Test Status = Not Run or Okay Intake Air Flow Control Valve Control Circuit Open Test Status = Not Run or Okay Intake Air Flow Control Valve Control Circuit Shorted Test Status = Not Run or Okay ⇒ If not the specified state Refer to: Circuit/System Testing ⇓ If the specified state
4. Perform the scan tool control function: Intake Air Flow Control Valve Position » Command the component to the maximum position/speed & Minimum position/speed Verify the following parameters are within 10% of each other: Intake Air Flow Control Valve Command Intake Air Flow Control Valve Position ⇒ If not within 10% of each other Refer to: Circuit/System Testing ⇓ If within 10% of each other
5. Perform the scan tool function: Clear the DTCs.
6. Ignition Off » For greater than 1 min
7. Ignition » On / Vehicle » In Service Mode
8. Verify DTC P02E0, P02E3, P02EB, P122B, P122C, P1425 is not set. ⇒ If any of the DTCs are set Refer to: Circuit/System Testing ⇓ If none of the DTCs are set
9. Engine » Idling
10. Verify the scan tool parameter: Intake Air Flow Control Valve Control Circuit High Test Status = Not Run or Okay Intake Air Flow Control Valve Control Circuit Low Test Status = Not Run or Okay Intake Air Flow Control Valve Control Circuit Open Test Status = Not Run or Okay Intake Air Flow Control Valve Control Circuit Shorted Test Status = Not Run or Okay – Perform the action while monitoring the parameter: Wiggle the harness and connector: Q20 Intake Airflow Control Valve Wiggle the harness and connector: K20 Engine Control Module ⇒ If not the specified state Refer to: Circuit/System Testing ⇓ If the specified state
11. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. Verify the DTC does not set. ⇒ If the DTC sets Refer to: Circuit/System Testing ⇓ If the DTC does not set
12. All OK. Circuit/System Testing
13. Ignition/Vehicle » Off
14. Verify the following conditions do not exist: Blade @ Q20 Intake Airflow Control Valve

Warning

Turn OFF the ignition before inserting fingers into the throttle bore. Unexpected movement of the throttle blade could cause personal injury. Binding or Sticking @ Open/Close — Position Closed @ Engine Off Coking / Debris / Dirty / Visible Damage Open/Close — Without spring pressure ⇒ If a condition exists Replace the component: Q20 Intake Airflow Control Valve ⇓ If no condition exists

Note

Disconnecting the component electrical connector causes additional DTCs to set.

3. Disconnect the electrical connector: Q20 Intake Airflow Control Valve
4. Ignition » On / Vehicle » In Service Mode
5. Test for 8 to 10 V between the test points: Control circuit terminal 1 @ Component harness & Ground Control circuit terminal 2 @ Component harness & Ground ⇒ If less than 8 V 5.1. Ignition/Vehicle » Off 5.2. Disconnect the appropriate electrical connector: K20 Engine Control Module 5.3. Test for infinite resistance between the test points: Control circuit terminal 1 @ Component harness & Ground Control circuit terminal 2 @ Component harness & Ground ⇒ If less than infinite resistance » Repair the short to ground on the circuit. ⇓ If infinite resistance 5.4. Test for infinite resistance between the test points: Control circuit terminal 1 & Control circuit terminal 2 ⇒ If less than infinite resistance » Repair the short between the circuits. ⇓ If infinite resistance 5.5. Test for less than 2 Ω between the test points: Control circuit terminal 1 @ Component harness & The other end of the circuit @ Control module harness Control circuit terminal 2 @ Component harness & The other end of the circuit @ Control module harness ⇒ If 2 Ω or greater » Repair the open/high resistance in the circuit. ⇒ If less than 2 Ω » Replace the component: K20 Engine Control Module ⇒ If greater than 10 V 5.1. Ignition/Vehicle » Off 5.2. Disconnect the appropriate electrical connector: K20 Engine Control Module 5.3. Ignition » On / Vehicle » In Service Mode 5.4. Test for less than 1 V between the test points: Control circuit terminal 1 @ Component harness & Ground Control circuit terminal 2 @ Component harness & Ground ⇒ If 1 V or greater » Repair the short to voltage on the circuit. ⇒ If less than 1 V » Replace the component: K20 Engine Control Module ⇓ If between 8 and 10 V
6. Connect a test lamp between the test points: Control circuit terminal 1 & Control circuit terminal 2
7. Perform the scan tool control function: Intake Air Flow Control Valve » Command the component to the maximum position/speed & Release Control Verify the test lamp turns On and Off. ⇒ If the test lamp does not turn On and Off Replace the component: K20 Engine Control Module ⇓ If the test lamp turns On and Off
8. Test or replace the component: Q20 Intake Airflow Control Valve Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Throttle Body Assembly Replacement — Q20 Intake Airflow Control Valve For control module replacement, programming, and setup refer to: Control Module References Additional Procedures

Note

The DTC causing the Driver Information Center message/speed limitation to set must run and pass before the message/speed limitation will clear. This may require driving the vehicle.

1. Ignition » On / Vehicle » In Service Mode
2. Verify that all scan tool Event Data parameters under the following data list displays No: Exhaust Gas Recirculation System Malfunction Warning Event Data ⇒ If not the specified state Operate the vehicle within the Conditions for Running the DTC for the DTC identified by the Event Data parameter displaying Yes. ⇓ If the specified state
3. All OK.