• | 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. |
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 | -- | -- |
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 |
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:
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.
• | 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. |
• | 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. |
• | 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. |
The ECM determines that the pressure sensor value change is less than a calibrated value.
• | 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. |
The pressure sensor signal is less than 0.2 volt for at least 12.5 seconds.
The pressure sensor signal is more than 4.8 volts for at least 12.5 seconds.
DTCs P2430, DTC P2431, DTC P2432, and DTC P2433 are Type B DTCs.
DTCs P2430, DTC P2431, DTC P2432, and DTC P2433 are Type B DTCs.
Secondary Air Injection System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If the air pump does not turn ON or OFF, refer to DTC P0411, P0412, P0418, P2440, or P2444. |
⇒ | If the solenoid does not click, refer to DTC P0411, P0412, P0418, P2440, or P2444. |
⇒ | 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. |
Note: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing or misdiagnosis may result.
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | 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 |
⇒ | 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. |
⇒ | 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. |
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. |
• | Control Module References for control module replacement, setup, and programming |