What Does P2528 Mean?
The PCM has detected an abnormally high voltage signal from the vacuum reservoir pressure sensor circuit. This indicates a short to voltage, open circuit, or faulty sensor providing incorrect readings.
Common Causes
35%
Open circuit in sensor signal wire or poor connection
30%
Failed vacuum reservoir pressure sensor with internal open
20%
Short to voltage in sensor signal circuit
10%
Disconnected or backed-out sensor connector pins
5%
Faulty sensor ground circuit
Diagnostic Steps
1
Step 1: Check voltage at the sensor connector with sensor disconnected (signal wire should read approximately 5V reference)
2
Step 2: Reconnect sensor and backprobe the signal wire to verify voltage drops appropriately when sensor is connected
3
Step 3: Inspect sensor connector for backed-out pins, loose terminals, or poor contact
4
Step 4: Check for open circuits in the signal wire by measuring continuity from sensor to PCM
5
Step 5: Test sensor operation by applying known vacuum and monitoring voltage output if possible
Estimated Repair Cost
$120 - $400
Parts + labor, varies by vehicle and location
The PCM has detected an abnormally high voltage signal from the vacuum reservoir pressure sensor circuit. This indicates a short to voltage, open circuit, or faulty sensor providing incorrect readings.
The most common cause of P2528 (Vacuum Reservoir Pressure Sensor Circuit High) is: Open circuit in sensor signal wire or poor connection
Typical repair costs for P2528 range from $120 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Brake boost system monitoring is compromised, which may lead to undetected vacuum loss. Braking performance could be degraded without driver warning.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2528 to identify the root cause.
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Quick Info
Category
Powertrain
System
Vacuum System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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