For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC P2430 : Secondary Air Injection (AIR) System Pressure Sensor Circuit
DTC P2431 : Secondary Air Injection System Pressure Sensor A Circuit Range/Performance
DTC P2432 : Secondary Air Injection System Pressure Sensor A Circuit Low
DTC P2433 : Air Injection System Pressure Sensor A Circuit High

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Pressure Sensor 5-Volt Reference Voltage | P2432 | P2431 | P2431 | P2430, P2431
Pressure Sensor Signal | P2432 | P2432 | P2433 | P2430, P2431
Pressure Sensor Low Reference | -- | P2433 | -- | --

### Typical Scan Tool Data

#### AIR Pressure Sensor

Circuit | Normal Range | Short to Ground | Open | Short to Voltage
--- | --- | --- | --- | ---
Operating Conditions: Key ON, Engine OFF
5-Volt Reference Voltage | BARO | 41 kPa | 41 kPa | 111 kPa
Pressure Sensor Signal | BARO | 42 kPa | 41 kPa | 150 kPa
Low Reference | BARO | BARO | 145 kPa | BARO

### Circuit/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 solenoid 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 engine control module (ECM) 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:

1. DTCs P0411 and P2430 run during Phase 1.
2. DTCs P2430 and P2440 run during Phase 2.
3. DTC P2444 runs during Phase 3.

During phase 1, both the AIR pump and the solenoid valve are activated. Normal secondary air function occurs. Expected system pressure is 8-10 kPa above barometric pressure (BARO).

During phase 2, only the AIR pump is activated. The solenoid valve is closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 20-25 kPa above BARO.

During phase 3, neither the AIR pump nor the solenoid valve is activated. AIR pump deactivation is tested. Expected system pressure equals BARO.

In all 3 phases, testing is accomplished by comparing the measured pressure against the expected pressure. The ECM 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.

### Conditions for Running the DTC

#### P2430

• | DTCs P0412, P0418, P0606, P1635, P1639, P2432, P2433 are not set.

• | More than 60 minutes has elapsed since the last cold start.

• | The AIR pump is commanded ON.

• | DTC P2430 runs continuously when the above conditions are met.

#### P2431

• | DTCs P0106, P0107, P0108, P0412, P0418, P0606, P1635, P1639, P2432, P2433 are not set.

• | The ignition is ON.

• | DTC P2431 runs continuously when the above conditions are met.

#### P2432 and P2433

• | DTCs P0606, P1635, P1639 are not set.

• | The ignition is ON or the engine is running.

• | DTC P2432 and 2433 run continuously when the above conditions are met.

### Conditions for Setting the DTC

#### P2430

The ECM determines that the pressure sensor value change is less than a calibrated value.

#### P2431

• | The ECM determines that the difference between the AIR pressure sensor and the BARO sensor signals is greater than 10 kPa when the AIR pump is commanded OFF.

| OR

• | The ECM determines that the difference between the AIR pressure sensor and the BARO sensor signals is greater than 50 kPa when the AIR pump is commanded ON.

#### P2432

The pressure sensor signal is less than 0.2 volt for at least 12.5 seconds.

#### P2433

The pressure sensor signal is more than 4.8 volts for at least 12.5 seconds.

### Action Taken When the DTC Sets

DTCs P2430, DTC P2431, DTC P2432, and DTC P2433 are Type B DTCs.

### Conditions for Clearing the MIL/DTC

DTCs P2430, DTC P2431, DTC P2432, and DTC P2433 are Type B DTCs.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Secondary Air Injection System Description

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Ignition ON, command the secondary air injection pump ON and OFF with a scan tool. The air pump should turn ON and OFF.

⇒ | If the air pump does not turn ON or OFF, refer to DTC P0411, P0412, P0418, P2440, or P2444.

2. Command the secondary air injection solenoid ON and OFF. The solenoid should click with each command.

⇒ | If the solenoid does not click, refer to DTC P0411, P0412, P0418, P2440, or P2444.

3. Engine running, command the secondary air injection pump ON while observing the secondary air injection pressure sensor parameter. The reading should be 20-25 kPa above the BARO reading.
4. Engine running, command the secondary air injection pump and the secondary air injection solenoid ON while observing the secondary air injection pressure sensor parameter. The reading should be 8-10 kPa above BARO.
5. Ignition ON, engine OFF, observe that the AIR Pressure Sensor parameter is within 3 kPa of the BARO parameter.

⇒ | If not the specified range, verify that the BARO parameter is correct for your altitude. Refer to Altitude Versus Barometric Pressure. If the BARO parameter is not correct for your altitude, refer to DTC P0106.

6. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

### Circuit/System Testing

Note: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing or misdiagnosis may result.

1. Ignition OFF, allow the ECM to completely power down.
2. Disconnect the harness connector at the AIR solenoid valve assembly.
3. Test for less than 5 ohms between the low reference circuit terminal 1 and ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.

⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM

5. Verify the scan tool AIR Pressure Sensor parameter is less than 0.5 volt.

⇒ | If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the ECM.

6. Install a 3A fused jumper wire between the signal circuit terminal 2 and the 5-volt reference circuit terminal 3. Verify the scan tool AIR Pressure Sensor parameter is greater than 4.9 volts.

⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

7. If all circuits tests normal, test or replace the AIR solenoid valve assembly.

### Component Testing

#### Solenoid

Apply appropriately fused battery voltage and ground to the solenoid terminals and verify that the valve opens and closes completely as voltage is applied to and removed from the solenoid terminals. Observe that the valve is not obstructed or leaking.

⇒ | If the valve operates incorrectly, leaks, or is obstructed, remove the obstruction or replace the AIR solenoid.

### Repair Instructions

• | Secondary Air Injection Pump Replacement

• | Secondary Air Injection Check Valve Replacement

• | Secondary Air Injection Pump Inlet Hose Replacement

• | Secondary Air Injection Pump Outlet Hose Replacement

• | Control Module References for control module replacement, setup, and programming

### Repair Verification

1. Engine running, observe that the AIR Pressure Sensor parameter approximately equals BARO.
2. Engine running, enable the AIR pump with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 20-25 kPa above BARO.
3. Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO.