P2440

P2440-AIR PUMP SWITCH VALVE STUCK OPEN

For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

Theory of Operation

For 20 seconds following a vehicle cold start, the air injection system delivers a controlled amount of outside air into the exhaust system, upstream of the catalytic converters, in order to help reduce hydrocarbon and carbon monoxide gas emissions.

- When Monitored:
Engine Coolant Temperature (ECT) above 0° C (32° F), intake temperature (IAT) within approximately 2 degrees of ECT. Measured airflow during pump actuation greater than a calibrated value (approximately 45 kg/h). Monitoring begins six seconds after the air injection pump turns off.

- Set Condition:
The Powertrain Control Module (PCM) detects that the difference between minimum and maximum secondary airflow during monitoring (with the pump off) is greater than 6 kg/h.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. DTC IS ACTIVE

WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to service any part of the exhaust system until it has cooled. Special care should be taken when working near any part of the exhaust system. The temperature rises to a high level after a short period of engine operating time.

NOTE: Diagnose and repair any Secondary Air system sensor signal or relay control circuit DTCs before proceeding with this procedure.

1. Turn the ignition on.
2. With the scan tool, select View DTCs and review the DTC environmental data for this DTC.

Is the good trip counter greater than 0?

Yes

- Perform the CHECKING FOR AN INTERMITTENT DTC diagnostic procedure. Checking for an Intermittent DTC.

No

- Go To 2

2. AIR INJECTION SYSTEM COMPONENT INSPECTION

WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to service any part of the exhaust system until it has cooled. Special care should be taken when working near any part of the exhaust system. The temperature rises to a high level after a short period of engine operating time.

1. Turn the ignition off.
2. Inspect the Secondary Air Pump Assembly, the Secondary Air Pump Valve and the connection tubes between them.
3. Look for evidence of heat damage at the Secondary Air Check Valve and at the Secondary Air Pump outlet tube. If the valve is stuck open, hot exhaust gases may melt or deform the pump outlet tube. Engine performance may also be affected.
4. Using the wiring diagram/schematic as a guide, inspect the wiring and electrical connectors at the Secondary Air Pump Assembly.
5. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

No

- Go To 3

3. SECONDARY AIR CHECK VALVE

WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to service any part of the exhaust system until it has cooled. Special care should be taken when working near any part of the exhaust system. The temperature rises to a high level after a short period of engine operating time.

1. Turn the ignition off.
2. Disconnect the air pump outlet tube (3) from the secondary air check valve (1).
3. Start the engine and allow it to idle for at least one minute.

Does exhaust gas leak from the Secondary Air Check valve inlet with the engine running?

Yes

- Replace the Secondary Air Check Valve.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

No

- Go To 4

4. (F343) FUSED MAIN RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE

1. Turn the ignition off.
2. Disconnect the C1 Secondary Air Pump Assembly harness connector.
3. Turn the ignition on.
4. Using a 12 volt test light connected to ground, check the (F343) Fused Main Relay Output circuit in the C1 Secondary Air Pump Assembly harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

Is the test light illuminated and bright?

Yes

- Go To 5

No

- Repair the (F343) Fused Main Relay Output circuit for an open circuit or high resistance.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

5. (K157) MAF SENSOR SIGNAL CIRCUIT VOLTAGE

1. Turn the ignition on.
2. Measure the voltage of the (K157) MAF Sensor Signal circuit in the C1 Secondary Air Pump Assembly harness connector.

Is the voltage between 4.8 and 5.1 volts?

Yes

- Go To 6

No

- Go To 7

6. (K957) MAF SENSOR GROUND CIRCUIT TEST

1. Turn the ignition off.
2. Using a 12-volt test light connected to 12 volts, check the (K957) MAF Sensor Ground circuit in the C1 Secondary Air Pump Assembly harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

Is the test light illuminated and bright?

Yes

- Go To 11

No

- Go To 10

7. (K157) MAF SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE

1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (K157) MAF Sensor Signal circuit in the C1 Secondary Air Pump Assembly harness connector.

Is there any voltage present?

Yes

- Repair the (K157) MAF Sensor Signal circuit for a short to voltage.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

No

- Go To 8

8. (K157) MAF SENSOR SIGNAL CIRCUIT SHORTED TO GROUND

1. Turn the ignition off.
2. Measure the resistance between ground and the (K157) MAF Sensor Signal circuit in the C1 Secondary Air Pump Assembly harness connector.

Is the resistance above 100 Ohms?

Yes

- Go To 9

No

- Repair the (K157) MAF Sensor Signal circuit for a short to ground.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

9. (K157) MAF SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

NOTE: When checking circuits at the Powertrain Control Module (PCM), be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.

1. Measure the resistance of the (K957) MAF Sensor Ground circuit between the C1 Secondary Air Pump Assembly harness connector and the PCM harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 12

No

- Repair the (K957) MAF Sensor Ground for an open circuit or high resistance.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

11. SECONDARY AIR PUMP ASSEMBLY
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Secondary Air Pump Assembly and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Search for any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

No

- Replace the Secondary Air Pump Assembly.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

12. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Secondary Air Pump Assembly and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM VERIFICATION TEST. PCM Verification Test.

No

- Replace the Powertrain Control Module (PCM).
- Perform the PCM VERIFICATION TEST. PCM Verification Test.