What Does P2518 Mean?
The PCM has detected a voltage signal from A/C refrigerant pressure sensor B that exceeds the acceptable maximum threshold. This suggests either an electrical circuit problem or an implausibly high pressure reading.
Common Causes
40%
Failed A/C refrigerant pressure sensor B reading high
25%
Short to voltage in sensor signal wire
20%
Open ground circuit in sensor ground wire
10%
Damaged sensor connector with pin-to-pin short
5%
Overcharged A/C system causing actual high pressure
Diagnostic Steps
1
Step 1: Inspect sensor connector for damage, bent pins, or contamination that could cause shorts
2
Step 2: Disconnect sensor and check voltage on signal wire at harness connector (should drop to ~0V or 5V depending on system design)
3
Step 3: Check for short to voltage in signal wire using ohmmeter with sensor disconnected and key off
4
Step 4: Verify sensor ground circuit continuity and resistance (should be less than 1 ohm to battery negative)
5
Step 5: Measure actual A/C system pressures with mechanical gauge to verify refrigerant charge is not excessive
Estimated Repair Cost
$120 - $450
Parts + labor, varies by vehicle and location
The PCM has detected a voltage signal from A/C refrigerant pressure sensor B that exceeds the acceptable maximum threshold. This suggests either an electrical circuit problem or an implausibly high pressure reading.
The most common cause of P2518 (A/C Refrigerant Pressure Sensor "B" Circuit High) is: Failed A/C refrigerant pressure sensor B reading high
Typical repair costs for P2518 range from $120 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
No immediate safety concern. A/C system may shut down to protect compressor from excessive pressure conditions.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2518 to identify the root cause.
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Quick Info
Category
Powertrain
System
A/C System and Engine Controls
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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