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DTC codes / GM codes / P1495

P1495 · GMLeak Detection Pump Solenoid Circuit Open Or Shorted

P1495 on a GM vehicle means the engine computer has detected an open circuit or a short to ground or power in the wiring for the leak detection pump solenoid, which is part of the evaporative emissions system. The computer commands the solenoid to move and then checks the electrical feedback; when the voltage or current falls outside the expected window, it stores this code and turns on the check engine light.

SystemPowertrain
Code typeGM specific
SeverityLow
Fix difficultyIntermediate
AreaAuxiliary emission controls

Symptoms you may notice

  • The check engine light is on, and often there are no other symptoms the driver can feel.
  • A faint fuel odor may be present around the rear of the vehicle if the solenoid is stuck and the system cannot seal.
  • Remote start may be disabled on some GM models as a protective measure when an emissions fault is active.
  • The vehicle may fail an emissions inspection because the evaporative system monitor cannot complete.
  • In rare cases, a shorted solenoid can blow the same fuse that feeds other emissions components, causing additional codes.

Common causes, most likely first

  1. Broken, chafed, or corroded wiring between the leak detection pump solenoid and the engine computer.
  2. A failed leak detection pump solenoid with an open coil or shorted windings.
  3. A loose or corroded electrical connector at the solenoid or at the computer.
  4. Water intrusion into the leak detection pump assembly or its connector, common on vehicles driven in wet or salty conditions.
  5. A short to ground or short to voltage on the solenoid control circuit caused by harness damage near the fuel tank or rear suspension.
  6. A failed engine computer driver for the solenoid circuit, which is rare but possible after a shorted solenoid overheats the driver.

How to diagnose and fix it

  1. Scan all modules and record freeze-frame data for P1495, then clear the code and verify whether it returns immediately with the key on or only after a commanded test.
  2. Visually inspect the leak detection pump solenoid connector and the harness along the rear underbody for chafing, corrosion, or water intrusion.
  3. Measure the resistance of the solenoid coil with a multimeter and compare it to the expected value for your GM model; an open or very low reading condemns the solenoid.
  4. With the key on and the solenoid disconnected, check for battery voltage on the feed circuit and verify the control circuit is not shorted to ground or power.
  5. Command the solenoid on and off with a scan tool while watching for a change in current or an audible click to confirm the computer driver and circuit are working.
  6. Repair or replace the damaged section of harness, clean and dielectric-grease the connector, or replace the leak detection pump assembly if the solenoid is faulty.
  7. Clear the codes, run the evaporative system monitor to completion, and confirm P1495 does not return before returning the vehicle to the customer.

What a P1495 often really means

  • A large share of P1495 cases on GM vehicles are caused by a corroded or water-filled connector at the leak detection pump rather than a failed solenoid, especially on trucks and SUVs that see road spray.
  • The code can set intermittently when the harness is flexed by suspension movement, so a wiggle test of the rear underbody harness while watching solenoid feedback is a valuable step that many technicians skip.
  • A shorted solenoid can damage the computer driver, so always check solenoid resistance before installing a replacement computer or you risk repeating the failure.
  • P1495 does not mean the evaporative system has a large leak; it is an electrical circuit fault, and a smoke test alone will not find the cause.
  • Some GM vehicles share the solenoid feed with other emissions devices, so a blown fuse can set P1495 together with unrelated codes and lead to misdiagnosis.

Can I keep driving with P1495?

The vehicle remains safe to drive because this is an emissions control circuit fault that does not affect engine performance or braking. Avoid topping off the fuel tank past the first click and have the circuit inspected soon so the evaporative monitor can run and the check engine light can be cleared.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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