A/C Request Circuit Malfunction
The P2522 code indicates a problem in the A/C request circuit, which is the signal from the A/C control module or switch to the Powertrain Control Module (PCM) requesting compressor engagement. This circuit typically involves a 5V reference, ground, and signal wire. When the PCM detects an abnormal voltage or signal, it sets this code. Common issues include a faulty A/C pressure sensor, wiring problems, or a defective A/C control module.
1. Most Common Causes
- A/C Request 'B' circuit shorted to ground or voltage
- A/C Request 'B' circuit open or high resistance
- Corroded, loose, or damaged connector or terminal in the circuit
- Faulty A/C request switch or button
- Defective HVAC control module
- Internal ECM failure in signal interpretation
2. Symptoms You Will Notice
- A/C compressor does not engage
- No cold air from vents
- A/C system blows warm air
- Check Engine Light illuminated
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to verify the code and check for related codes (e.g., P0530, P0532).
Step 2: Inspect the A/C pressure sensor connector for corrosion, damage, or loose pins.
Step 3: Test the A/C request signal wire between the sensor and PCM for continuity and shorts using a multimeter.
Step 4: Check the A/C pressure sensor's reference voltage (typically 5V) and ground circuits.
Step 5: If wiring is intact, replace the A/C pressure sensor and clear the code.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, but the A/C will not work. Driving without A/C is safe, but if the issue is electrical, it may affect other systems.
How much does it cost to fix?▼
Typically $100-$300, including parts (A/C pressure sensor ~$50-$100) and labor (1-2 hours).
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.