• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Pressure Sensor 5-Volt Reference Voltage | P2432 | P2432 | P2431 | P2430, P2431 |
Pressure Sensor Signal | P2432 | P2432 | P2433 | P2430, P2431 |
Pressure Sensor Low Reference | -- | P2433 | -- | -- |
Pump Voltage Supply | P0411 | P0411 | P2444 | -- |
Pump Ground | -- | P0411 | -- | -- |
Solenoid Voltage Supply | P0411 | P0411 | P2440 | -- |
Solenoid Ground | -- | P0411 | -- | -- |
Pump Relay Coil Voltage Supply | P0411, P0418 | P0411, P0418 | -- | -- |
Pump Relay Coil Control | P0418, P2444 | P0411, P0418 | P0418 | -- |
Pump Relay Switch Supply | P0411 | P0411 | -- | -- |
Solenoid Relay Coil Voltage Supply | P0411, P0412 | P0411, P0412 | -- | -- |
Solenoid Relay Coil Control | P0412, P2440 | P0411, P0412 | P0412 | -- |
Solenoid Relay Switch Supply | P0411 | P0411 | -- | -- |
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 valve 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 powertrain control module (PCM) 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 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 15-20 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 PCM 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 P0606, P0641, P0651 are not set. |
• | The ignition is ON or the engine is running. |
• | DTC P2432 runs continuously when the above conditions are met. |
The pressure sensor signal is less than 0.2 volt for at least 12.5 seconds.
DTC P2432 is a Type B DTC.
DTC P2432 is a Type B DTC.
Engine running, observe that the AIR Pressure Sensor parameter approximately equals BARO.
Important: The Circuit/System Verification must be performed first 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 PCM. |
⇒ | 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 PCM. |
⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the PCM. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the PCM. |
⇒ | If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the PCM. |
⇒ | If the valve operates incorrectly, leaks, or is obstructed, remove the obstruction or replace the valve. |
• | Control Module References for control module replacement, setup and programming |
With the engine running, enable the AIR pump with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 15-20 kPa above BARO.