What Does P2403 Mean?
The PCM is not receiving a signal from the leak detection pump sense circuit, indicating an open circuit or communication failure. The sense circuit monitors pump operation and pressure changes.
Common Causes
40%
Failed leak detection pump with inoperative sense circuit or switch
30%
Open or damaged wiring in sense circuit between pump and PCM
20%
Corroded or damaged connector pins at pump or PCM
10%
Failed pressure sensor or switch internal to leak detection pump
Diagnostic Steps
1
Step 1: Inspect leak detection pump connector for corrosion, damage, or moisture intrusion
2
Step 2: Check continuity in sense circuit wiring from pump connector to PCM
3
Step 3: With pump connected, monitor sense circuit voltage/signal with scan tool during pump operation
4
Step 4: Check for proper voltage reference signal from PCM to pump sense circuit (typically 5V)
5
Step 5: Test pump functionality by commanding pump on and listening/feeling for operation
Estimated Repair Cost
$200 - $650
Parts + labor, varies by vehicle and location
The PCM is not receiving a signal from the leak detection pump sense circuit, indicating an open circuit or communication failure. The sense circuit monitors pump operation and pressure changes.
The most common cause of P2403 (Evaporative Emission System Leak Detection Pump Sense Circuit/Open) is: Failed leak detection pump with inoperative sense circuit or switch
Typical repair costs for P2403 range from $200 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
No safety concern for vehicle operation. Will cause emissions test failure and prevent EVAP system leak detection from functioning.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2403 to identify the root cause.
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Quick Info
Category
Powertrain
System
Evaporative Emissions System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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