DTC 612: Fuel Tank System, Small Leak
- Check status message on Volvo Scan Tool (998-8686 ). If fault is PERMANENT, SMALL LEAK, perform all procedures in next step. If fault is INTERMITTENT, SMALL LEAK, check for defective components as outlined in next step.
- Ensure fuel tank filler cap is on correctly and seal is intact. Check EVAP canister, rollover valve, EVAP canister shut-off valve and fuel tank hoses, and hose connectors. Repair as necessary. If no faults are found, go to next step.
- Start and idle engine. Using scan tool, go into scrolling values. If fuel tank pressure drops when CP valve opens, go to next step. If fuel tank pressure does not drop when CP valve opens, go to step 6).NOTE: Following step pressurizes fuel tank. Ensure tank does not contain more than 8 gallons of fuel.
- Ensure ignition is off. Remove EVAP canister shut-off valve from its bracket. Clamp hose between CP valve and intake manifold. Carefully disconnect EVAP canister hose from CP valve. Connect Pressure Gauge (999 5646 ) to hose and Pressure Regulator (999 5544 ) to EVAP canister. Set pressure at one psi (.07 kg/cm2 ). Open cock valve on pressure gauge. Let pressure build for 5 minutes, ensuring pressure does not increase beyond maximum .15 psi (.010 kg/cm2 ). Shut off cock valve. Read off pressure after 10 minutes.
- If pressure does not stabilize, go to step 7). If pressure stabilizes, check connectors and hose to EVAP canister shut-off valve for airtightness. If components are okay, go to next step. If components are not okay, go to step 7).
- Turn ignition off. Remove fuel tank pressure sensor located in front of fuel pump. Check all hoses and nipples for blockage. Repair as necessary. If hoses are okay, replace fuel tank pressure sensor.
- Ensure ignition is off. Pressurize fuel tank as outlined in step 4). Spray soapy water on fuel tank, fuel hoses and other components. It may be necessary to lower fuel tank to gain access to hoses and connectors on top of tank. Repair as necessary.