Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Enabling Conditions To Run EVAP Leak Detection Test
- Cold start: with ambient temperature (obtained from modeling the inlet air temperature sensor on passenger vehicles and the battery temperature sensor on Jeep & truck vehicles) between 4°C (40°F) and 32°C (90°F) for 0.040 leak. Between 4°C (40°F) and 29°C (85°F) for 0.020 leak.
- Engine coolant temperature within: -12° to -8°C (10° to 18°F) of battery/ambient.
- Battery voltage between 10 and 15 volts.NOTE: If battery voltage drops below 10 volts for more than 5 seconds during engine cranking, the EVAP Leak Detection Test will not run. RUN.
- Low fuel warning light off (fuel level must be between 15% and 85%).
- MAP sensor reading 22 in Hg or above (This is the manifold absolute pressure, not vacuum).
- No engine stall during test.NOTE: The following values are approximate and vehicle specific. Use the values seen in pretest/monitor test screen on the DRBIII®. See TSB 25-02-98 for more detail.
A DTC will not set if a one-trip fault is set or if the MIL is illuminated for any of the following:
- Purge Solenoid
- All engine Controller Self Test Faults
- All Cam and/or Crank Sensor Faults
- MAP Sensor Faults
- Ambient/Battery Temperature Sensor Electrical Faults
- All Coolant Sensor Faults
- All TPS Faults
- LDP Pressure Switch Faults
- EGR Solenoid Electrical Faults
- All Injector Faults
- Baro Out Of Range
- Vehicle Speed Faults
- LDP Solenoid Circuit
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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