DTC P0411 (WITH RPO CODE NU3)
SYSTEM DESCRIPTION
The secondary air injection (AIR) system aids in the reduction of hydrocarbon emissions during a cold start. The system forces fresh filtered air into the exhaust stream in order to accelerate the catalyst operation. An electric air pump, the secondary AIR injection pump, provides filtered air on demand to the AIR control solenoid valve/pressure sensor assembly. The AIR control solenoid valve/pressure sensor assembly controls the flow of air from the AIR pump to the exhaust manifold. The AIR valve relay supplies the current needed to operate the AIR control solenoid valve/pressure sensor assembly. A pressure sensor is used to monitor the air flow from the AIR pump. The powertrain control module (PCM) supplies the internal pressure sensor with a 5-volt reference, an electrical ground, and a signal circuit.
The AIR diagnostic uses 3 phases to test the AIR system:
DTCs P0411 and P2430 run during Phase 1
DTCs P2430 and P2440 run during Phase 2
DTC P2444 runs during Phase 3
In all 3 phases, testing is accomplished by comparing the measured pressure against the expected pressure. The PCM can detect faults in the AIR pump, AIR control solenoid valve/pressure sensor assembly, and the exhaust check valve. The pressure sensor can also detect leaks and restrictions in the secondary AIR system plumbing.
DTC P0411 Secondary Air Injection (AIR) System Insufficient Flow diagnostic monitors system airflow. This diagnostic test detects insufficient system flow due to a malfunctioning AIR control solenoid valve/pressure sensor assembly or AIR valve relay; a malfunctioning AIR pump or AIR pump relay; or a restricted or leaking system. When the PCM detects AIR system flow is not sufficient DTC P0411 sets. DTC P0411 runs during Phase 1.
Phase 1
The PCM commands the AIR pump ON and the AIR control/shut-off valve OPEN.
The AIR system flow is sufficient and DTC P0411 passes. DTC P0411 AIR diagnostic proceeds to Phase 2.
The AIR system flow is not sufficient. DTC P0411 AIR diagnostic fails, testing is stopped and DTC P0411 sets.
DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0411 Secondary Air Injection (AIR) System Insufficient Flow
CONDITIONS FOR RUNNING THE DTC
DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0201-P0206, P0300, P0350, P0412, P0418, P0420, P0606, P0641, P0651, P1350, P2430, P2431, P2432, P2433 are not set.
The system voltage is between 10-18 volts.
The engine is running.
The start-up engine coolant temperature (ECT) is between 5-50°C (41-122°F)
The start-up intake air temperature (IAT) is between 5-60°C (41-140°F)
The BARO parameter is more than 60 kPa.
The MAF sensor parameter is between 3-24 g/s.
DTC P0411 runs once per trip start up when the above conditions are met and AIR pump operation is requested.
CONDITIONS FOR SETTING THE DTC
The AIR system does not meet expected flow conditions during AIR pump Phase 1 operation.
DTC P0411 sets with in 22 seconds when the above conditions are met.
ACTION TAKEN WHEN THE DTC SETS
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
DIAGNOSTIC AIDS
An intermittent may be caused by any of the following conditions:
Low system airflow
Excessive exhaust system back-pressure
Pinched, restricted, split, or damaged pipes/hoses
Restrictions in the AIR pump inlet hose
Pitted contacts in the AIR pump relay, AIR valve relay-Tap on the AIR pump relay or AIR valve relay to attempt to duplicate an intermittent condition.
Yellow tinted water in the AIR pump may indicate a control/shut-off valve failure.
Water or debris ingested into the AIR pump
Observe the Freeze Frame/Failure Records to aid in conditions of setting DTC P0411.
Thoroughly inspect any circuits that are suspected of causing the intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections. See: Powertrain Management Computers and Control Systems Testing and Inspection Initial Inspection and Diagnostic Overview Diagnostic Strategies
TEST DESCRIPTION
Steps 1-9
Steps 10-18
Steps 19-23
Steps 24-30
Steps 31-41
Steps 42-55
Steps 56-62
The numbers below refer to the step numbers on the diagnostic table.
This step determines if excessive resistance on the supply voltage circuit between the AIR pump fuse and the AIR pump relay is the cause for an inoperative AIR pump. One ohm of resistance on this circuit can prevent the AIR pump from running.
This step determines if excessive resistance on the AIR pump relay circuit and PCM driver is the cause for an inoperative AIR pump relay. The test lamp in series is intended to generate a electrical load on this circuit. Fifty ohms of resistance on this circuit can prevent the AIR pump relay from operating.
This step determines if excessive resistance on the supply circuit is the cause for an inoperative AIR pump. One ohm of resistance on this circuit can prevent the AIR pump from running.
This step determines if excessive resistance on the ground circuit is the cause for an inoperative AIR pump. One ohm of resistance on this circuit can prevent the AIR pump from running.
This step commands both the AIR pump and AIR valve relays ON.
This step determines if the AIR system is operating normally. When the AIR valve relay is commanded ON the AIR pump should run with the AIR control/shut-off valve OPEN.
Wednesday, July 29th, 2020 AT 5:57 PM
(Merged)