P122B Buick 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 Buick 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 Buick 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 Buick?
- 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 Buick?
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 Buick 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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Frequently Asked Questions about P122B Buick Code
1. What does the OBDII code P122B mean on a Buick?
P122B refers to an issue with the Intake Air Flow Valve Control Supply Voltage Circuit, indicating a problem with the electrical supply or control of the intake air valve.
2. What are the common symptoms of a P122B code on a Buick?
Symptoms may include reduced engine performance, poor acceleration, rough idling, stalling, and the check engine light being illuminated.
3. What causes the P122B code to be triggered?
Common causes include a faulty intake air flow valve, damaged wiring or connectors in the circuit, a malfunctioning engine control module (ECM), or a blown fuse.
4. Can I drive my Buick with a P122B code?
While the vehicle may still be drivable, it could experience performance issues. It's best to address the issue promptly to avoid potential engine damage or unsafe driving conditions.
5. How can I diagnose the P122B code on my Buick?
Start by inspecting the wiring and connectors for damage, checking the intake air flow valve for proper operation, and testing the circuit voltage with a multimeter.
6. How is the P122B code typically fixed?
Repairs may involve replacing the intake air flow valve, repairing or replacing damaged wiring or connectors, or addressing ECM issues if necessary.
7. What tools are needed to diagnose and fix the P122B code?
You’ll need an OBDII scanner, a multimeter for checking voltage, and potentially basic hand tools for inspecting and replacing components.
8. Can a dirty air filter cause the P122B code?
While unlikely, a severely clogged air filter may indirectly contribute to intake air flow issues, so it’s worth inspecting the filter during diagnostics.
9. How much does it cost to fix a P122B code on a Buick?
Repair costs can vary widely depending on the cause, ranging from $50 for minor wiring repairs to $300 or more if replacing the intake air flow valve is necessary.
10. Can a software update resolve the P122B code on a Buick?
In some cases, a software update for the ECM may resolve the issue if it is related to incorrect programming or calibration. Consult your dealership for details.
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