Diagnostic Instructions

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

P2431

P2432 and P2433

Conditions for Setting the DTC

P2430

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

P2431

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

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 3 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 1 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 1. 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.

Repair Instructions

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.