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.
Circuit Description
PCM monitors amount of vacuum/pressure in EVAP system by monitoring fuel tank pressure sensor signal. PCM seals the EVAP system by commanding the EVAP purge solenoid off and EVAP vent valve on. PCM monitors fuel tank pressure sensor in order to determine if EVAP purge solenoid is leaking vacuum to EVAP system. This DTC sets if vacuum in EVAP system is greater than a predetermined value within a predetermined time.
DTC will set when following conditions are present:
- DTCs P0107, P0108, P0112, P0113, P0121, P0122, P0123, P0420, P0430, P0500, P0502, P0503, P1112, P1114, P1115 and HO2S related DTCs not set.
- Ignition voltage 10-17 volts.
- BARO pressure greater than 75 kPa.
- Fuel level 15-85 percent of full capacity.
- ECT and IAT 39-86°F (4-30°C).
- Start-up ECT and IAT are within 16°F (9°C) of each other.
- EVAP purge solenoid duty cycle is zero percent.
- TP angle between zero and 99 percent.
- EVAP system develops a vacuum greater than a predetermined value when purge is not commanded.
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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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