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.
Vacuum hoses and connections test
- 30. Do the fuel tank vapor control valve tests (see
FUEL TANK VAPOR CONTROL VALVE TEST ).
Is the fuel tank vapor control valve OK?
- YES -Go to step 31.
- NO -Replace the fuel tank vapor control valve.
- 31. Tighten the fuel cap 3 "clicks", then monitor the FTP readings with the HDS.
- 32. Start the engine, and let the engine idle 5 minutes.
- 33. Check the FTP sensor reading with the HDS.
Is the reading above 0.5 kPa (0.16 in.Hg, 4 mmHg), pressure, below - 4 mmHg vacuum, or about 3 V?
- YES -Update the ECM if it does not have the latest software, or substitute a known-good ECM; 2000-2001 M/T models (see HOW TO TROUBLESHOOT CIRCUITS AT THE ECM ), 2002-2005 M/T models and CVT model (see ECM UPDATING AND SUBSTITUTION FOR TESTING-2006 M/T MODELS AND CVT MODEL ), then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM (see ECM REPLACEMENT ).
- NO
-Check these parts for leaks:
- Fuel tank (A)
- Fuel fill cap (B)
- Fuel fill pipe(C)
- Fuel tank vapor control valve (D)
- Fuel tank vapor recirculation valve (E)
- Fuel tank vapor recirculation tube (F)
- Fuel tank vapor signal tube (G)
- Fuel tank vapor control vent tube (H)
- If necessary, repair or replace the parts.
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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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