What Does P2406 Mean?
The leak detection pump sense circuit voltage is reading higher than expected. This indicates a short to voltage, open circuit, or faulty leak detection pump in the EVAP system.
Common Causes
35%
Damaged or shorted wiring harness to leak detection pump
30%
Faulty leak detection pump internal sensor
20%
Corroded or damaged electrical connector at pump
10%
Failed powertrain control module (PCM)
5%
Short to voltage in circuit between PCM and pump
Diagnostic Steps
1
Step 1: Inspect leak detection pump connector for corrosion, damage, or moisture intrusion
2
Step 2: Measure voltage at pump sense circuit with key on engine off (should be near 5V reference)
3
Step 3: Disconnect pump and check for voltage drop; if voltage remains high, trace wiring for short to power
4
Step 4: Test leak detection pump resistance and operation according to manufacturer specifications
5
Step 5: If all wiring and pump test good, suspect PCM fault and verify with manufacturer diagnostics
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
The leak detection pump sense circuit voltage is reading higher than expected. This indicates a short to voltage, open circuit, or faulty leak detection pump in the EVAP system.
The most common cause of P2406 (Evaporative Emission System Leak Detection Pump Sense Circuit High) is: Damaged or shorted wiring harness to leak detection pump
Typical repair costs for P2406 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive. Only affects emissions system functionality and may cause failed emissions testing.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2406 to identify the root cause.
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Quick Info
Category
Powertrain
System
Evaporative Emissions System
Difficulty
Type
Generic (SAE)
Recommended Tools
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