DTC P02E1 or P02E5

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5507631 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 P02E1 Intake Air Flow Control Valve Control Performance DTC P02E5 Intake Air Flow Control Valve Stuck Closed Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performanc
Control — Terminal 1	P122C	P02E0	P122C, P122D	P1425
Control — Terminal 2	P122C	P02E0	P122C, P122D	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
	© 2023 Gener	al Motors. All rights reserved.

Component	Description
	sensors, interprets the data and adjusts the engine actuators accordingly.
Q38 Throttle Body	The intake air flow valve of diesel engines reduces the intake air flow rate in part load operation so that a higher exhaust gas recirculation rate can be achieved.

Conditions for Running the DTC P02E1 DTC P0071, P0072, P0074, P0116-P0119, P0128, P02E8, P02E9, P111E, U0654 = Not set Ambient Air Temperature = Warmer than −20°C (−4°F) Engine Coolant Temperature = Warmer than 30°C (86°F) Ignition and Start Switch Signal = On or Engine = Running Ignition and Start Signal = Greater than 11 V Intake Air Flow Control Valve Position = Steady State — For greater than 1 s Frequency the DTC runs = Continuously — After the running conditions are met — For greater than 1 s P02E5 DTC P02E0-P02E3, P02E8, P02E9, P02EB, P122B, P122C, P122D, P1425, U0654 = Not set DTC P02E1 is set. Engine = Off — For greater than 2 s Frequency the DTC runs = Continuously — After the running conditions are met — For greater than 1 s Conditions for Setting the DTC P02E1 Control Circuit = Commanded state does not match the actual state — For greater than 10 s P02E5 Intake Air Flow Control Valve Position = Less than 75% Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type A DTC Additional actions taken: Reduced Engine Power = Active P16 Instrument Cluster = 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. If the throttle blade becomes stuck, a DTC will set. Depending on the position of the throttle blade, the engine control module (ECM) may enter Engine Shutdown Mode. The ECM will disable fuel and de-energize the throttle actuator. If the condition remains present during the next ignition cycle, the ECM may disable engine cranking. Inspect the throttle body assembly for a stuck throttle blade if a throttle actuator DTC is current and the engine won’t crank. Inspect for a condition in which the throttle blade may have been held open. For example, ice may have formed in the throttle bore causing the throttle blade not to close. 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. Ignition » On / Vehicle » In Service Mode
2. Verify DTC P02E8, P02E9, U0654 is not set. ⇒ If any of the DTCs are set Refer to: DTC P02E8, P02E9, or U0654 ⇓ If none of the DTCs are set
3. Engine at Idle 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 ⇒ If not the specified state Refer to: Circuit/System Testing ⇓ If the specified state
4. Clear the DTCs.
5. Ignition Off » For greater than 1 min
6. Ignition » On / Vehicle » In Service Mode
7. Verify DTC P02E1, P02E5 is not set. ⇒ If the DTC sets Refer to: Circuit/System Testing ⇓ If the DTC does not set
8. 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
9. All OK. Circuit/System Testing
10. Ignition/Vehicle » Off
11. Verify the following conditions do not exist: Blade @ Q38 Throttle Body

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 Water intrusion — Ice ⇒ If a condition exists Test or replace the component: Q38 Throttle Body ⇓ If no condition exists

Note

Disconnecting the component electrical connector causes additional DTCs to set.

3. Disconnect the electrical connector: Q38 Throttle Body
4. Ignition » On / Vehicle » In Service Mode
5. Test for 8 to 9 V between the test points: Control circuit terminal 1 @ & Ground Control circuit terminal 2 @ & 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 @ Component harness ⇒ 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 9 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 9 V
6. Connect a test lamp between the test points: Control circuit terminal 1 & Control circuit terminal 2 @ Component harness
7. Perform the scan tool control function: Intake Air Flow Control Valve » Increase & Decrease
8. Verify the test lamp turns On and Off. ⇒ If the test lamp does not turn On and Off 8.1. Ignition/Vehicle » Off Remove » Test Lamp 8.2. Disconnect the appropriate electrical connector: K20 Engine Control Module 8.3. 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 the test lamp turns On and Off
9. Test or replace the component: Q38 Throttle Body Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Throttle Body Assembly Replacement — Q38 Throttle Body For the system learn/reset procedure refer to: Control Module References 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.