What Does P2405 Mean?
The PCM has detected abnormally low voltage in the leak detection pump sense circuit. This indicates a short to ground, failed sensor, or circuit malfunction preventing proper pump monitoring.
Common Causes
35%
Short to ground in sense circuit wiring harness
30%
Failed leak detection pump with shorted internal pressure sensor
20%
Damaged or chafed wiring near pump or along chassis
15%
Corroded connector causing internal short at pump or PCM
Diagnostic Steps
1
Step 1: Disconnect leak detection pump connector and check if code clears/returns to isolate pump vs wiring
2
Step 2: With pump disconnected, measure resistance to ground on sense circuit wire (should be high resistance)
3
Step 3: Inspect wiring harness for damage, particularly near heat sources, sharp edges, and body penetrations
4
Step 4: Check voltage reference circuit to pump for proper 5V signal from PCM
5
Step 5: Test leak detection pump sense circuit output with pump disconnected and powered separately
Estimated Repair Cost
$180 - $600
Parts + labor, varies by vehicle and location
The PCM has detected abnormally low voltage in the leak detection pump sense circuit. This indicates a short to ground, failed sensor, or circuit malfunction preventing proper pump monitoring.
The most common cause of P2405 (Evaporative Emission System Leak Detection Pump Sense Circuit Low) is: Short to ground in sense circuit wiring harness
Typical repair costs for P2405 range from $180 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
No safety risk for driving. Emissions system leak detection will not function and vehicle will fail emissions testing.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2405 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Evaporative Emissions System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
