A/C Request Circuit Low
The P2523 code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the A/C request circuit. This circuit carries the signal from the A/C control head to the PCM, which then engages the A/C compressor clutch. A low voltage reading suggests a short to ground, open circuit, or faulty component in the signal path, preventing proper A/C operation.
01. 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 or head unit
- Corroded or loose connector at PCM or A/C components
02. Symptoms You Will Notice
- A/C compressor does not engage
- No cold air from vents
- A/C system inoperative
- Check Engine Light illuminated
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and verify P2523 is present.
Step 2: Inspect A/C request circuit wiring and connectors for damage, corrosion, or shorts.
Step 3: Test A/C pressure sensor signal voltage with a multimeter (should be 0.5-4.5V).
Step 4: Check A/C control module output to PCM using a scan tool or wiring diagram.
Step 5: If wiring and sensors are okay, suspect faulty PCM (rare).
04. Commonly Affected Makes
05. 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 could affect other systems. It's best to diagnose promptly.
How much does it cost to fix?▼
Typically $50-$150 for diagnosis and repair, but costs can vary if a sensor or module needs replacement.