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2011 cadillac dts
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Discussion Starter #1
I still have the issue. But I got some info that it may be the intake that it may be bad. One thing that I notice that the intake is very dury with oil. One more thing my car has 205,000 mi I use it for livery service. I'm not buy one this car again.
 

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2011 DTS Platinum
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Secondary Air Injection System Incorrect Flow Detected

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.

Potential causes of a P0411 code include:

Damaged or missing check valve
AIR pump intake port plugged/damaged
AIR pump clutch malfunction
Holes or damage to exhaust components
 

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In may last post to you I ask you to check the pressure at the check valve by Taking offthe hose when the car was cold.
Different cars check the secondary system in many ways. ON the DTS it checks it in 3 phases. So you must fallow the proper chart for that car. If you replace the pump first and had a bad check valve, more then likely the pump is bad. You can kill a pump in 2 weeks with a bad check valve. If you look at the chart your problem is more likely in phase 1. That’s why I ask you to check the air pressure. If air is not 8-15 kpa above the BARO sensor you may not have enough air pressure from the pump .

One other note. After its fix it will take about 200miles to set all the flags so you can get a sticker.





P0411


The secondary airinjection (AIR) system aids in the reduction of hydrocarbon emissions during acold start. The system forces fresh filtered air into the exhaust stream inorder to accelerate the catalyst operation. The secondary AIR injection pump provides filtered air on demand to the AIR solenoid check valve assembly. TheAIR solenoid valve assembly controls the flow of air from the AIR pump to theexhaust manifold. The AIR pump relay supplies the current needed to operate theAIR pump. The AIR solenoid valve assembly has an integral check valve, pressuresensor, and solenoid valve. The pressure sensor monitors the air flow pressurefrom the AIR pump. The engine control module (ECM) supplies the internalpressure sensor with a 5-volt reference, a low reference, and a signal circuit.The signal circuit provides the control module with a voltage relative tointernal air pressure changes.
The AIR diagnostic uses 3phases to test the AIR system:





DTCsP0411 and P2430 run during Phase1












DTCsP2430 and P2440 run during Phase2












DTCP2444 runs during Phase3





During phase1, both the AIR pump and thesolenoid valve are activated. Normal secondary air function occurs. Expectedsystem pressure is 8–15kPaabove BARO.

During phase2, only the AIR pump isactivated. The solenoid valve is closed. Pressure sensor performance andsolenoid valve deactivation are tested. Expected system pressure is 15–22kPa above BARO.

During phase3, neither the AIR pump northe solenoid valve isactivated. AIR pump deactivation is tested. Expected system pressure equalsBARO.
In all 3phases, testing isaccomplished by comparing the measured pressure against the expected pressure.The control module can detect faults in the AIR pump, AIR solenoid, pressure sensor, and theexhaust check valve. The pressure sensor can also detect leaks and restrictionsin the secondary AIR system plumbing.

Conditionsfor Running the DTC









DTCsP0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0201–P0208, P0300, P0301–P0308, P0351–P0358, P0412, P0418, P0420, P0606, P0641, P0651, P2430, P2431, P2432, P2433, P2440, 2444 are not set.












The system voltage is between 11–18volts.












The start-up intake air temperature (IAT) is greater than 5°C (41°F).












The start-up engine coolant temperature (ECT) is between 5–80°C (41–176°F).












The AIR system is commanded ON.












The conditions are stable for greater than 5seconds.












DTCP0411 runs once per trip start-up when the above conditions are met and the AIR pump operation is requested.






Conditionsfor Setting the DTC









The ECM determines that the difference between the predicted system pressure and the actual system pressure is greater than 5kPa.







OR







The ECM determines that the difference between the predicted system pressure and the actual system pressure is less than−5kPa.












DTCP0411 sets during phase1 and within 22seconds when the above conditions are met.





 

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2011 cadillac dts
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Discussion Starter #4
superjim I had try everything to solve this problem I change the airpump the checkvalve the pipe are not damage I had try everything possible. And I still have the same issue, the pump come on but the code still there. I do not want to sell the car because of this issue, but I do not have the money to take to the dealer for them to find out the problem. I just want to know if some one had the same issue that I have.

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we check that the baro pressure with the dealer scanner it goes up let say from the baro pressure 101 to 120 then when the pump goes off it come back to 101 that match the air pressure. at one point we notice that the baro pressure and the air pressure where not matching and it was a clog map sensor we change it and it back to normal but I still have the same problem . One other thing that I notice the last couple of days the the pump is not coming on when I start the car first thing in the morning but if I turn the car off and start it right of way them the pump come on. This has happen only for couple of days.
 
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