2016 Chevy Silverado P2400 EVAP Leak Detection Pump Control Circuit Open

Question

My Check Engine light came on and I'm getting code P2400 on my scanner. The truck seems to run fine, but I can't clear the code and need to pass emissions next week. I am worried there is a break in the wiring harness somewhere near the fuel tank.

Chris Donovan · Accepted Answer

The issue turned out to be a broken signal wire about 6 inches up from the pump connector. The wire had rubbed against a plastic clip on the frame and snapped inside the insulation. I cut out the bad section, soldered in a new 18-gauge lead, and used marine-grade heat shrink to seal it. Cleared the code P2400 and it hasn't returned after three drive cycles. Total cost was about $5 for the wire and solder.

wrenchqueen · Answer

If the wiring looks good, it is likely the Evaporative Emissions Leak Detection Pump itself. It's part of the charcoal canister assembly on these Silverados. Sometimes the pump motor fails internally due to dust intrusion if the vent filter is clogged.

Pete Sanders · Answer

Check the connector at the EVAP canister above the spare tire. These are notorious for getting corrosion in the pins or having the wires rub through against the frame rail. Use a multimeter to see if you are getting 12V at the harness side with the key on.

Carlos Diaz · Answer

P2400 specifically points to an electrical issue, not necessarily a leak. You need to check the resistance of the leak detection pump solenoid. If the circuit is open internally in the pump, that code will trigger immediately when the ECM tries to run the monitor.

2016 Chevy Silverado P2400 EVAP Leak Detection Pump Control Circuit Open

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