A/C Request Circuit Low
The P2523 code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition on the A/C request circuit. This circuit carries a signal from the A/C control head to the PCM, requesting compressor engagement. A low voltage reading suggests a short to ground, open circuit, or faulty component, preventing the A/C system from activating.
1. Most Common Causes
- Faulty A/C pressure sensor
- Short to ground in A/C request circuit wiring
- Open circuit in A/C request circuit
- Faulty A/C control module
- Corroded or loose connector at PCM or A/C control head
2. Symptoms You Will Notice
- A/C compressor does not engage
- No cold air from vents
- A/C system inoperative
- Possible check engine light illumination
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to verify the code and check for related codes.
Step 2: Inspect the A/C request circuit wiring and connectors for damage, corrosion, or shorts.
Step 3: Test the A/C pressure sensor signal voltage with a multimeter (should be 0.5-4.5V).
Step 4: Check for continuity between the A/C control module and PCM.
Step 5: If wiring is intact, replace the A/C pressure sensor or control module as needed.
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 underlying issue is a short, it may affect other systems.
How much does it cost to fix?▼
Typically $50-$150 for diagnosis and repair, depending on the cause. Sensor replacement costs around $30-$80 plus labor.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.