I have a 1996 VW Passat GLX VR6 2.8L my MIL came on today ran a OBD2 came up P0411 (Secondary Air Injection System Incorrect Flow Detected) and P0172 (System Too Rich bank 1 sensor 1) i then followed up with a VAG-COM test for mor info on this and a ****** problem and it showed the same. i narrowed it down to the Air pump not kicking on. i've tested the pump it works fine. then i tested for voltage to the pump, there was none. then i checked the wiring between the air pump relay and the pump it was fine had good continuity. then i checked the relay itself and it is also good, it clicks and has continuity where it should. the ground for the relay has continuity. so I've narrowed it down to one wire a brown and white one ( the wire that sends a positive signal to the relay to kick on the pump but i don't exactly know where to go from here i know this wire goes into the wiring harness and then to the computer but i don't know what would cause this not to have a signal. i'll attach the wiring diagram for the relay to the pump to the computer.
Had the same problem on an '01 Cabrio. Everything else checked out there were no vacuum leaks or bad wires.
The problem was a 30 amp fuse located outside the engine fuse box under its own cover. Not a regular fuse this one is just a two inch strip of metal. Mine just had a tiny crack in it. I wouldn't have found it if someone else didn't post the same problem on another forum.
hope this helps.
Thank you I had found the blown fuse (more like torn) and I've been looking for a replacement for a while now with no luck. Since I don't know the proper name of the fuse I'm not able to just do a google search to find it and the part stores are clueless. May I ask where you found your replacement or if you know what to call the fuse.
Thanks in advance
I got mine from the local dealership. Only cost me a couple of dollars. I didn't know what to call it either so I took the old one in with me.
×
Hi there:DTC P0411 refer at Secondary Air Injection is an emission control that uses an air pump (either electric or turned by the drive belt) to move fresh air into the exhaust manifold(s) or exhaust ports when the engine is in open loop and pre-catalytic converter when in closed loop. This reduces hydrocarbon emissions (HC), Carbon Monoxide (CO), and oxides of Nitrogen (NOx). This fresh air helps convert Carbon Monoxide (CO) into Carbon Dioxide (CO2) and Hydrocarbons (HC) into water vapor (H20). A check valve is located in the air supply line to keep exhaust gasses from flowing into the pump. A cutoff valve that controls the airflow may be vacuum controlled or electrically controlled. When the powertrain control module (PCM) activates the valve, vacuum travels to the cutoff valve to open it and allow fresh air to flow. Some systems may have only a check valve and the flow may be regulated by a electromagnetic clutch on the air pump (similar to an A/C clutch). Under hard acceleration, the air pump will be deactivated to prevent backfiring in the exhaust. To self-check, the AIR system will be activated by the PCM and fresh air would be routed into the exhaust system. The oxygen sensors would sense this fresh air as a lean condition and the short term fuel trims would begin to move in the positive direction to compensate. The PCM expects to see this happen within just a few seconds during the self test. If it does not see the short term fuel trims rise, then the PCM interprets this as a malfunction in the AIR system and a code will be recorded. About the possible solutions, 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. Now,
DTC P0172 basically this means that an oxygen sensor in bank 1 detected a rich condition (too little oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1. This DTC is very similar to P0175, and in fact your vehicle may show both codes at the same time.
A code P0172 may mean that one or more of the following has happened:
- The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
- There could be a vacuum leak.
- There could be a fuel pressure or delivery problem
Possible solutions include:
- Inspect all vacuum and PCV hoses, replace if necessary
- Cleanthe MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
- Inspect fuel lines for cracks, leaks, or pinches
- Check the fuel pressure at the fuel rail
- Check the fuel injectors, they may be dirty. Use fuel injector cleaner or get them professionally cleaned/replaced.
- Check for an exhaust leak before the first oxygen sensor (this is unlikely to cause the problem, but it is possible)
Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.
Thank you for using FixYa, have a nice day.
SOURCE: 1996 Ford F-150 XL with
the EGR valve isnt working ,disconnect any vacumn pipes that run to the valve and wires and leave it like that unless you want to fit a new one ,an older vehicle never had this contraption fitted ,they always give problem when vehicle is older so if the vehicle runs then leave it disconnected .
SOURCE: P0411 Secondary Air Injection System Incorrect
There is a air leak in the vaccume system for the engine most of the time
3,868 views
Usually answered in minutes!
×