DTC P122D

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5507635 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 P122D Intake Air Flow Control Valve Position Sensor Exceeded Learning Limit 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 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.
	Q38 Throttle Body	The intake air flow valve of diesel engines reduces the intake air flow rate in part load operation so that a
	© 2023 Gener	alh Migohteorr se.x hAallu rsitg ghatss rreesceirrcvuelda.tion rate can be achieved.

Component	Description
	The component is actuated by a bidirectional DC motor. Not Activated = Open

Conditions for Running the DTC DTC P0071–P0074, P0116–P0119, P02E0–P02E5, P02E8, P02E9, P02EB, P0651, P122B, P122C, P1425, U0654 = Not set Ambient Air Temperature = Warmer than −9°C (15.8°F) Engine Coolant Temperature = 30 to 150°C (86 to 302°F) Ignition Key = Off Ignition and Start Signal = Greater than 5 V Intake Air Flow Control Valve Command = Learning — Complete Frequency the DTC runs = Continuously — After the running conditions are met Conditions for Setting the DTC Intake Air Flow Valve Learned Closed Position ≠ 4.3 to 4.6 V or Intake Air Flow Valve Learned Open Position ≠ 0.5 to 1.5 V 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. 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 P02E0–P02E5, P02E8, P02E9, P02EB, P122B, P122C, P1425, U0654 is not set. ⇒ If the DTC is set Refer to: Diagnostic Trouble Code (DTC) List - Vehicle ⇓ If the DTC is not set
3. Clear the DTCs.
4. Ignition Off » For greater than 1 min
5. Ignition » On / Vehicle » In Service Mode
6. Verify DTC P122D is not set. ⇒ If the DTC sets 6.1. Ignition/Vehicle » Off 6.2. 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 » Repair or replace as necessary ⇓ If the DTC does not set

7. 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 Repeat step 2 ⇓ If the DTC does not set
8. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Throttle Body Assembly Replacement — Q38 Throttle Body 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.