P122D Code - Intake Air Flow Valve Position Sensor Exceeded Learning Limit
Quick Answer
The intake airflow 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. Common causes include Faulty Intake Air Flow Valve, Intake Air Flow Valve harness is open or shorted, Intake Air Flow Valve circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P122D indicates Intake Air Flow Valve Position Sensor Exceeded Learning Limit.
- Common causes
- Common causes include Faulty Intake Air Flow Valve, Intake Air Flow Valve harness is open or shorted, Intake Air Flow Valve circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P122D Description
The Intake airflow valve assembly contains a contactless inductive throttle position sensing element that is managed by a customized integrated circuit. The valve position sensor is mounted within the valve body assembly and is not serviceable. The Engine Control Module (ECM) supplies the valve body with a 5 V reference circuit, a low reference circuit, an H-bridge motor directional control circuit, and an asynchronous signal/serial data circuit. The asynchronous signal means communication is only going from the intake airflow valve to the ECM. The Intake Air Flow Valve cannot receive data from the ECM over the signal/serial data circuit. The valve position sensor provides a signal voltage that changes relative to the valve blade angle. The valve position sensor information is transmitted between the Intake Air Flow Valve and the ECM on the signal/serial data circuit.
The valve may also be used to shut down the engine by closing the intake airflow valve and disabling the fuel injectors if the control module detects the engine speed is beyond the desired control limits. The Diagnostic Trouble Code (DTC) will be set if the ECM detects the Intake air flow valve learned closed position is not 4.25 - 4.70 V
What are the Possible Causes of the DTC P122D?
- Faulty Intake Air Flow Valve
- Intake Air Flow Valve harness is open or shorted
- Intake Air Flow Valve circuit poor electrical connection
How to Fix the DTC P122D?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P122D code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Information for Specific Makes
- P122D Buick — Intake Air Flow Valve Position Sensor Exceeded Learning Limit
- P122D Cadillac — Intake Air Flow Valve Position Sensor Exceeded Learning Limit
- P122D Chevrolet — Intake Air Flow Valve Position Sensor Exceeded Learning Limit
- P122D GMC — Intake Air Flow Valve Position Sensor Exceeded Learning Limit
Frequently Asked Questions about P122D Code
1. What are the common symptoms of OBDII code P122D - Intake Air Flow Valve Position Sensor Exceeded Learning Limit?
- Common symptoms include rough idling, decreased engine performance, decreased fuel efficiency, and potential stalling.
2. What are the possible causes of OBDII code P122D?
- The code P122D can be caused by a faulty intake air flow valve position sensor, wiring issues, vacuum leaks, or a dirty air filter.
3. How can I diagnose the issue related to OBDII code P122D?
- Diagnosing the issue involves checking the intake air flow valve position sensor, inspecting the wiring for any damage, checking for vacuum leaks, and ensuring the air filter is clean.
4. Can a dirty air filter trigger OBDII code P122D?
- Yes, a dirty air filter can disrupt the airflow, impacting the intake air flow valve position sensor readings and potentially triggering the code P122D.
5. How serious is OBDII code P122D - Intake Air Flow Valve Position Sensor Exceeded Learning Limit?
- While the code may not cause immediate harm to the vehicle, it can lead to decreased engine performance and fuel efficiency if left unresolved.
6. What are some recommended repair tips for resolving OBDII code P122D?
- Repair tips include cleaning or replacing the air filter, checking and repairing any damaged wiring, inspecting and possibly replacing the intake air flow valve position sensor, and addressing any vacuum leaks.
7. Can driving with OBDII code P122D cause further damage to the vehicle?
- Continuing to drive with the code may not cause immediate damage, but it can lead to worsening engine performance and fuel efficiency over time.
8. How much does it typically cost to repair OBDII code P122D?
- The cost of repairing the code can vary depending on the specific issue, but it may range from $100 to $500, including parts and labor.
9. Can I reset OBDII code P122D myself, or do I need a professional?
- You can attempt to reset the code using an OBDII scanner, but it is recommended to diagnose and address the underlying issue to prevent the code from reoccurring.
10. How long can I safely drive with OBDII code P122D before getting it fixed?
- It is advisable to address the issue as soon as possible to prevent further deterioration in engine performance and fuel efficiency.
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