2001 regal LS 3800

[toad5200]

HI every body have code po410 AIR system malfunction I found water in the AIR pump blew it out and dried. the pump runs. I think there is a check valve in the system .I can here a sound from the AIR pump that sounds like an exhaust leak.does this make any sense? If so would some one please tell me the location of the one way check valve.THANKS P. s.any other ideas are very much welcome.

[BNaylor]

Oh, green state CA NC8 emissions option. There is a GM TSB out that mentions adding a protection-shield to the secondary air pump to prevent the water damage. P0410 could be the air pump or check valve. The check valve should be located either with the pump or between the pump and exhaust system since it prevents exhaust backflow. Also, I've heard a bad CAT can cause that DTC error code and nothing may be wrong with the air pump or check valve.

If you have a 2001 - 2002, the CAT warranty was extended by GM to 10 years or 120K miles, whichever comes first. They were delivered with flaky CATs.

[BNaylor]

This is the only data I have concerning your problem. This is applicable to GM 3.5/3.8L engines with secondary air injector - RPO code NC8. Hopefully the info helps. Good luck!


CIRCUIT DESCRIPTION
The AIR pump is used on this vehicle to lower tail pipe emissions on start-up. The Powertrain Control Module (PCM) grounds the AIR pump relay control circuit, which energizes the AIR pump. The PCM also grounds the AIR solenoid valve control circuit, which energizes the AIR solenoid valve. The AIR solenoid valve opens allowing manifold vacuum to open the AIR control valves. The PCM enables both control circuits when AIR system operation is desired. When the AIR system is active, the AIR pump forces fresh air into the exhaust stream in order to accelerate catalyst operation. The AIR control valves replace the conventional check valves. When the AIR system is inactive, the AIR control valves prevent air flow in either direction. DTC P0412 applies to the AIR solenoid control circuit. DTC P0418 applies to the AIR pump relay control circuit.

DTC P0410 sets if an air flow problem is detected. The PCM will run two tests using the Heated Oxygen Sensor (HO2S) voltage to diagnose the AIR system. Both tests have two parts.

The passive test is performed during regular AIR pump operation. The passive test consists of the following:

Passive Test Part 1
When the AIR system is enabled, the PCM monitors the HO2S voltage. If the HO2S voltage goes below a threshold, the PCM interprets this as an indication that the AIR system is operational.

Passive Test Part 2
When the AIR system is disabled, the PCM monitors the HO2S voltage. The HO2S voltage should increase above a threshold and switch normally.

If both of these tests indicate a pass, no further action is taken. If one of the above tests failed or is inconclusive, the diagnostic will proceed to test two. The active test is performed specifically for diagnostic purposes. Test two consists of the following:

Active Test Part 1
During this test the PCM turns the AIR system on during closed loop operation. When the AIR system is activated, the PCM monitors the HO2S voltage. If the AIR system is operating properly, the HO2S voltage should go below a predetermined threshold.

Active Test Part 2
The PCM turns the AIR system off. The HO2S voltage should return to above a rich threshold.

The PCM will repeat test two up to 4 consecutive times with a short delay between each command.

If the PCM determines that the HO2S voltage did not respond as expected during the tests, DTC P0410 will set.

CONDITIONS FOR RUNNING THE DTC

DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0171, P0172, P0300, P0412, P0418, P0442, P0443, P1441 and HO2S DTCs not set.
The engine operates for more than 3 seconds .
Test 1

The engine speed is more than 400 RPM
The engine load is less than 80 percent .
The engine air flow is less than 35 g/s .
The ignition voltage is more than 11.5 volts .
The air fuel ratio is more than 13:1.
The Engine Coolant Temperature (ECT) is less than 40°C (104°F) .
The Intake Air Temperature (IAT) is more than 10°C (50°F) .
The power enrichment, deceleration fuel cut off, or catalyst over temperature not active.
The AIR system is enabled for 50 seconds . On a hot start, the AIR system operation will be delayed for 60 seconds after start-up.
Test 1 fails if:
HO2S voltage does not go below 300 mV for 25 seconds during pump operation.
HO2S voltage does not go above 600 mV during the 15 seconds after the pump is turned off.
Test 2

The engine operates for more than 5 minutes .
The engine speed is more than 400 RPM .
The EVAP purge is active
The maximum air flow is 35 g/s .
The ECT is more than 10°C (50°F) .
The ignition voltage is more than 11.5 volts .
The engine load is less than 80 percent .
The fuel system is operating in closed loop.
Test 2 fails if the HO2S voltage is above 300 mV for 4 seconds during pump operation.
CONDITIONS FOR SETTING THE DTC
If the HO2S voltage does not behave as expected during either of the tests, a failure is reported.

ACTION TAKEN WHEN THE DTC SETS

The PCM illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC

The PCM turns the MIL OFF after three consecutive drive trips during which the diagnostic runs and passes.
A last test tailed, or the current DTC, clears when the diagnostic runs and passes.
A History DTC clears after forty consecutive warm-up cycles, if no other emission related diagnostic failures are reported.
Use a scan tool in order to clear the MIL diagnostic trouble code.
Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description, Clearing Diagnostic Trouble Codes.
DIAGNOSTIC AIDS

NOTE:

Refer to Connector Test Adapter Kit J 35616-A Notice in Service Precautions.
Refer to Continuous Operation of the Air Pump Notice in Service Precautions.
Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid in determining how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same Freeze Frame conditions, such as RPM, load, vehicle speed, temperature, etc., that you observed This will isolate when the DTC failed.

If the problem is intermittent, refer to Intermittent Conditions. See: Diagnosis By Symptom\Intermittent Conditions

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.

DTC P0412 AIR Solenoid Valve Control Circuit and P0418 AIR Pump Relay Control Circuit should be diagnosed first if either are set.
The AIR pump is not designed to run continuously. If the pump needs to be replaced, check for conditions that may cause continuous pump operation.