P122B GMC Code - Intake Air Flow Valve Control Supply Voltage Circuit
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 Throttle Body Assembly, Throttle Body Assembly harness is open or shorted, Throttle Body Assembly 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
- P122B GMC indicates Intake Air Flow Valve Control Supply Voltage Circuit.
- Common causes
- Common causes include Faulty Throttle Body Assembly, Throttle Body Assembly harness is open or shorted, Throttle Body Assembly 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 P122B GMC 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 an open circuit on the intake airflow valve control circuit.
What are the Possible Causes of the DTC P122B GMC?
- Faulty Throttle Body Assembly
- Throttle Body Assembly harness is open or shorted
- Throttle Body Assembly circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P122B GMC?
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 P122B GMC 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 GMC Models
- P122B 2014 GMC Sierra — Intake Air Flow Valve Control Supply Voltage Circuit
- P122B 2015 GMC Sierra — Intake Air Flow Valve Control Supply Voltage Circuit
- P122B 2016 GMC Sierra — Intake Air Flow Valve Control Supply Voltage Circuit
- P122B 2017 GMC Sierra — Intake Air Flow Valve Control Supply Voltage Circuit
- P122B 2018 GMC Sierra — Intake Air Flow Valve Control Supply Voltage Circuit
Frequently Asked Questions about P122B GMC Code
1. What are common symptoms of OBDII code P122B GMC related to the Intake Air Flow Valve Control Supply Voltage Circuit?
- Common symptoms include engine stalling, rough idle, lack of power, and potential issues with acceleration.
2. What are the potential causes of OBDII code P122B GMC?
- Possible causes include a faulty intake air flow valve, damaged wiring or connectors in the supply voltage circuit, or a malfunctioning PCM.
3. How can I diagnose the issue causing OBDII code P122B GMC?
- To diagnose the problem, you can start by inspecting the intake air flow valve, checking the wiring and connectors for any damage, and using a scan tool to gather data from the PCM.
4. What should I check first when troubleshooting OBDII code P122B GMC?
- It is recommended to check the intake air flow valve and its related components first, as they are commonly the source of the issue.
5. Can I drive my vehicle with OBDII code P122B GMC present?
- It is not advisable to drive your vehicle with this code present, as it can lead to further damage and potential safety risks.
6. How can I repair OBDII code P122B GMC related to the Intake Air Flow Valve Control Supply Voltage Circuit?
- Repair options may include replacing the intake air flow valve, repairing damaged wiring or connectors, or reprogramming the PCM if necessary.
7. Are there any DIY tips for fixing OBDII code P122B GMC?
- While some basic troubleshooting can be done at home, it is recommended to seek professional help for accurate diagnosis and repair of this issue.
8. How much does it typically cost to fix OBDII code P122B GMC?
- The cost of repairs can vary depending on the exact cause of the issue, but it may range from $100 to $500 or more, including parts and labor.
9. Can a faulty intake air flow valve cause OBDII code P122B GMC?
- Yes, a faulty intake air flow valve is a common culprit for triggering this specific OBDII trouble code.
10. Is it important to address OBDII code P122B GMC promptly?
- Yes, it is crucial to address this code promptly to prevent further damage to your vehicle and ensure optimal performance and safety.
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