P2431
DTC P2430 or P2431
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle
* Review Strategy Based Diagnosis Strategy Based Diagnosis
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions
DTC Descriptor
DTC P2430
- Secondary Air Injection System Pressure Sensor Circuit
DTC P2431
- Secondary Air Injection System Pressure Sensor Performance
Circuit/System Description
The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A pressure sensor in the shutoff/check valve is used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5-volt reference circuit and supplies a ground to the low reference circuit. The sensor provides a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.
Ignition voltage is supplied to the secondary air injection pump and air injection shutoff/check valve relays. The ECM controls the relays by grounding the control circuits, which activates the relays. When the relay contacts close, voltage is supplied to the pump and the valve, which turns the pump on and opens the valve.
The diagnostic uses 3 phases to test the secondary air injection system:
* DTCs P0411 and P2430 run during Phase 1
* DTCs P2430 and P2440 run during Phase 2
* DTC P2444 runs during Phase 3
During phase 1, the secondary air injection pump and the secondary air injection shutoff and check valve are activated. Normal secondary air function occurs. Expected system pressure is 5-13 kPa (0.7-1.9 psi) above BARO.
During phase 2, only the secondary air injection pump is activated. The shutoff and check valve is closed. Pressure sensor performance and shutoff and check valve deactivation are tested. Expected system pressure is 14-25 kPa (2.0-3.6 psi) above BARO.
During phase 3, neither the secondary air injection pump nor the secondary air injection shutoff and check valve are activated. Secondary air injection pump deactivation is tested. Expected system pressure equals BARO.
Conditions for Running the DTC
P2430
* DTC P0412, P0418, P0606, P2431, P2432, or P2433 is not set.
* Greater than 30 min has elapsed since the last cold start.
* The ignition voltage is between 10-32 V.
* The engine speed is less than 5,000 RPM.
* The intake air temperature (IAT) is greater than -11°C (12.2°F).
* The engine coolant temperature (ECT) is between -11 and +56°C (12.2-133°F).
* The barometric pressure (BARO) is greater than 74 kPa (10.7 psi).
* The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
* The mass air flow (MAF) is less than 50 g/s.
* The secondary air injection pump is commanded ON.
* DTC P2430 runs once per ignition cycle when the above conditions are met for greater than 5 s.
P2431
* DTC P0101, P0102, P0103, P0300, P0301, P0302, P0303, P0304, P2430, P2432, or P2433 is not set.
* Greater than 30 min has elapsed since the last cold start.
* The ignition voltage is between 10-32 V.
* The engine speed is less than 5,000 RPM.
* The intake air temperature (IAT) is greater than -11°C (12.2°F).
* The engine coolant temperature (ECT) is between -11 and +56°C (12.2-133°F).
* The barometric pressure (BARO) is greater than 74 kPa (10.7 psi).
* The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
* The mass air flow (MAF) is less than 50 g/s.
* DTC P2431 runs continuously when the above conditions are met for greater than 15 s.
Conditions for Setting the DTC
P2430
The ECM determines that the pressure sensor value change at the shutoff/check valve is less than 0.5 kPa and the signal variation is less than 0.15 kPa for greater than 5 s when the secondary air injection pump is commanded ON.
P2431
* The difference between the actual system pressure at the shutoff/check valve and BARO is greater than 18 kPa (2.6 psi) or less than -10 kPa -1.5 psi) for greater than 5 s when the secondary air injection pump is commanded OFF.
OR
* The difference between the actual system pressure at the shutoff/check valve and BARO is greater than 50 kPa (7.3 psi) for greater than 5 s when the secondary air injection pump is commanded ON.
Action Taken When the DTC Sets
DTCs P2430 and P2431 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P2430 and P2431 are Type B DTCs.
Diagnostic Aids
Ice buildup due to condensation/water in the air passages or pump may cause this DTC to set.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Secondary Air Injection System Description Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Special Tools
EL 36169-HD - Fused Jumper
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Verification
Note: Verify the battery is fully charged before proceeding with this diagnostic procedure. The secondary air injection pump output will vary with system voltage.
1. Ignition ON
2. Verify that DTC P0412, P0418, P2432, P2433, P2440, or P2444 is not set.
• If any of the DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
• If none of the DTCs are set.
3. Verify the scan tool BARO pressure parameter is within the range specified in the Altitude Versus Barometric Pressure Altitude Versus Barometric Pressure table.
• If not within the specified range
Refer to DTC P2227-P2230 P2227.
• If within the specified range
4. Verify the scan tool Secondary Air Injection Pressure Sensor and the BARO pressure parameters are within 3 kPa (0.4 psi).
• If not within the specified range
Replace the Q29 Secondary Air Injection Solenoid Valve
• If within the specified range
Note: To prevent the secondary air injection pump from overheating, do not operate the pump consecutively for greater than 2 minutes. The pump is provided with a thermal protector that will automatically reset when allowed to cool.
5. Verify the G21 Secondary Air Injection Pump turns ON and OFF when commanding the Secondary Air Injection Pump Relay between ON and OFF with a scan tool.
• If the pump does not turn ON and OFF
Refer to Circuit/System Testing-Secondary Air Injection Pump Malfunction
• If the pump turns ON and OFF
6. Engine running
7. Verify the scan tool Secondary Air Injection Pressure Sensor parameter increases between 14-25 kPa (2.0-3.6 psi) when the Secondary Air Injection Pump Relay is commanded ON with a scan tool.
• If not within the specified range
Refer to Circuit/System Testing-Secondary Air Injection System Pressure Not In Range.
• If within the specified range
8. Verify the scan tool Secondary Air Injection Pressure Sensor parameter increases between 5-13 kPa (0.7-1.9 psi) when the Secondary Air Injection System is commanded Active with a scan tool.
• If not within the specified range
Refer to Circuit/System Testing-Secondary Air Injection System Pressure Not In Range.
• If within the specified range
9. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
10. Verify the DTC does not set.
• If the DTC sets
Refer to Circuit/System Testing
• If the DTC does not set
11. All OK
Circuit/System Testing
Secondary Air Injection Pump Malfunction
1. Ignition OFF, disconnect the KR25 Secondary Air Injection Pump Relay. Ignition ON.
2. Verify a test lamp illuminates between the B+ circuit terminal 30 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF
2. Test for infinite resistance between the B+ circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Disconnect the harness connector at the G21 Secondary Air Injection Pump.
4. Test for infinite resistance between the control circuit terminal A and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
5. Test or replace the G21 Secondary Air Injection Pump.
• If the test lamp illuminates
3. Disconnect the harness connector at the G21 Secondary Air Injection Pump.
4. Ignition OFF and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 ohms between the G21 Secondary Air Injection Pump ground circuit terminal B and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
5. Connect the harness connector at the G21 Secondary Air Injection Pump.
6. Connect a 50 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87.
Note: To prevent the secondary air injection pump from overheating, do not operate the pump consecutively for greater than 2 minutes. The pump is provided with a thermal protector that will automatically reset when allowed to cool.
7. Verify the G21 Secondary Air Injection Pump is activated.
• If the pump does not activate
1. Ignition OFF, disconnect the harness connector at the G21 Secondary Air Injection Pump.
2. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms,
3. Test or replace the G21 Secondary Air Injection Pump.
• If the pump activates
8. Test or replace the KR25 Secondary Air Injection Pump Relay.
Secondary Air Injection System Pressure Not In Range
1. Verify the following conditions do not exist with the secondary air injection shutoff and check valve:
* Hoses/pipes restricted or blocked
* Hoses/pipes leaking or disconnected
* Damaged secondary air injection shutoff and check valve
* Restricted or blocked cylinder head secondary air injection inlet ports and passages
• If a condition is located
Repair or replace the affected component as necessary.
• If all components test normal
2. Disconnect the secondary air injection hoses/pipe from the Q29 Secondary Air Injection Solenoid Valve.
3. Ignition ON, command the Secondary Air Injection Pump Relay ON with a scan tool.
4. Verify airflow to the Q29 Secondary Air Injection Solenoid Valve.
• If no airflow
Replace the G21 Secondary Air Injection Pump.
• If airflow
5. Disconnect the appropriate Q29 Secondary Air Injection Solenoid Valve from the engine.
6. Connect the harness connector at the Q29 Secondary Air Injection Solenoid Valve.
7. Connect the secondary air injection pipe between the Q29 Secondary Air Injection Solenoid Valve and the G21 Secondary Air Injection Pump.
8. Ignition ON, command the Secondary Air Injection System Active with a scan tool. Verify there is airflow through the valve.
• If no airflow
Replace the Q29 Secondary Air Injection Solenoid Valve
• If airflow
9. Replace the G21 Secondary Air Injection Pump.
Component Testing
Relay Test
1. Ignition OFF, disconnect the KR25 Secondary Air Injection Pump Relay.
2. Test for 70-110 ohms between terminals 85-86.
• If less than 70 ohms or greater than 110 ohms
Replace the KR25 Secondary Air Injection Pump Relay.
• If between 70-110 ohms
3. Test for infinite resistance between the terminals listed below:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
• If less than infinite resistance
Replace the KR25 Secondary Air Injection Pump Relay.
• If infinite resistance
4. Install a 15 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground.
5. Test for less than 2 ohms between terminals 30 and 87.
• If 2 ohms or greater
Replace the KR25 Secondary Air Injection Pump Relay.
• If less than 2 ohms
6. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)
* Secondary Air Injection Pump Replacement Service and Repair
* Secondary Air Injection Check Valve Replacement Service and Repair for secondary air injection solenoid valve replacement
* Secondary Air Injection Pump Pipe Replacement Secondary Air Injection Pump Pipe Replacement