New code P0411 ?????
- Thread starter tireman
- Start date
tireman
Dedicated LVC Member
checked everything out and system working as expected. replacing oxygen sensors, will update when completed.
replaced oxy sensors, all 4 replaced, still P0411, will update when problem found.
replaced oxy sensors, all 4 replaced, still P0411, will update when problem found.
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Dewanjd
2003 lincoln ls
If you have access to a scan tool, with KOEO (Key on engine off) command the AIR pump on. It should activate. If it doesn't, remove and inspect the AIR pump relay for discoloration/melting due to heat. Repair as necessary. With the ignition on (engine off) check for battery voltage at the switched battery feed to the relay and the relay control circuit. If either of these isn't present, inspect circuit for blown fuse or open/short in the wiring. Repair cause of short and retest. If they are both present, jumper the battery feed to AIR pump feed circuit using a fused jumper. The pump should activate. If not, check for power and ground present at the AIR pump when jumpered. If there is no voltage/ground present at pump repair open in wiring harness. If voltage and ground is present, but pump still does not run, suspect a bad AIR pump. If after jumpering the AIR pump feed circuit the pump activates then the problem is likely the AIR pump relay. Replace and retest. If the scan tool activates the AIR pump, with KOER (Key on engine running) activate the AIR pump solenoid valve on and see if there is vacuum to the cutoff valve. It should have vacuum present to open the valve. If there is no vacuum present, check the AIR pump's vacuum solenoid valve for vacuum supply from the manifold. If there is vacuum present then the vacuum solenoid is likely bad. Replace it. If there is no vacuum present at the supply to the vacuum solenoid, check for a plugged or damaged vacuum line or plugged vacuum port. But if there is vacuum present at the cut-off valve, shut the engine off and using a vacuum pump, apply vacuum to the cut-off valve and see if it holds a vacuum and that air flows through it when vacuum is applied. If it doesn't hold vacuum or the valve doesn't flow when vacuum is applied, replace the cut-off valve. If the cut-off valve works properly, inspect the check valve for obstruction or to see if it's missing. Replace as necessary. Check the steel line to the exhaust catalyst as well as the exhaust ports for damage or holes that could give a false reading.
tireman
Dedicated LVC Member
Found problem, it was the diverter valve solenoid. Checked vacuum line, vacuum good to charcoal filter and to solenoid. Removed solenoid and checked resistence, good = 50-100ohms, checked good. Replaced solenoid with a Dorman 600-400 solenoid $17. Fixed it. I guess the solenoid was sticking.
Tireman, was the solenoid easy to access. Is it attached to the air pump. I ran the KOEO (Key on engine off) to command the AIR pump on. I could hear the pump turn on. The Check eng light will come on every 5-7 days after clearing it. The check eng light came 2 days ago and cleared itself today.
tireman
Dedicated LVC Member
The solenoid is up front of the engine, just in front of the alternator. You can reach it by hand, no screws or bolts, you will need a long screw driver with a flat blade to shimmy the hoses loose and the clip edge on the solenoid back. You must reach it from below, you will need ramps or jack stands to hold the car up. There is a clip on top of the electrical connector, i broke mine but thats ok. do you have a V6?,,,,,,,,once your car is jacked up, you can go under and see the diverter valve plainly in front of the engine, there is a flexible hose coming from the air pump that you can pull off the valve to check for air to the valve.
you can reach the diverter valve from the driver side and the solenoid from the passenger side. check for vacuum on the charcoal canister w/engine running. remove line and feel for vacuum, if ok then the other side to the solenoid should be good too. both devices use the same vacuum port.
once the vac line was taken off the solenoid and connector to the valve, i pulled them up to engine level and checked for vac. It was good.
you can reach the diverter valve from the driver side and the solenoid from the passenger side. check for vacuum on the charcoal canister w/engine running. remove line and feel for vacuum, if ok then the other side to the solenoid should be good too. both devices use the same vacuum port.
once the vac line was taken off the solenoid and connector to the valve, i pulled them up to engine level and checked for vac. It was good.
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tireman
Dedicated LVC Member
TIP - reach up over the diverter valve on the drivers side and remove the vacuum line from the diverter valve. then from the passenger side push down on the solenoid to release it, there is a clip lip on the back of the solenoid. pull the solenoid out with the electrical connector and vacuum lines attached, they will reach to below the alternator. Then swap the solenoid, reinstall with the lines attached. Then go over the diverter valve again to reattach the vacuum line.