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 CircuitDTC 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 | -- | -- |
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 | -- | -- |
Typical Scan Tool Data
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:
- 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, 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, P2431, P2432, and P2433 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P2430, P2431, P2432, and P2433 are Type B DTCs.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, verify that the AIR pump is not activated.
- Ignition ON, observe that the AIR Pressure Sensor parameter approximately equals the BARO parameter.
- 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.
- 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.
| ⇒ | If not equal, verify that the BARO parameter reading is correct for your altitude. Refer to Altitude Versus Barometric Pressure . If the reading is not correct for your altitude, diagnose the manifold absolute pressure (MAP) sensor. Refer to DTC P0106 . If the BARO parameter is correct for your altitude, proceed with Circuit/System Testing. |
| ⇒ | If less than the specified range, verify that the AIR pump is activating. If AIR pump activation is normal, proceed with Circuit/System Testing. |
Circuit/System Testing
Important: The Circuit/System Verification must be performed first or misdiagnosis may result.
- Ignition OFF, disconnect the harness connector at the AIR solenoid valve.
- Ignition OFF, test for less than 1 ohm between the low reference circuit terminal 1 and ground.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
- Verify the scan tool AIR Pressure Sensor parameter is less than 0.5 volt.
- 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.
- Connect all electrical connectors.
- Ignition ON, engine OFF, observe the AIR Pressure Sensor parameter.
- 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.
- Remove the AIR inlet hose from the AIR pump.
- Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter increases to 8-10 kPa above BARO.
- Disconnect the hose from the AIR pump outlet.
- Disconnect the hose quick-connect from the AIR solenoid valve inlet.
- Install a length of standard 25.4 mm (1 inch I.D.) hose from the AIR pump outlet to the AIR solenoid valve inlet.
- Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter increases to 8-10 kPa above BARO.
- Remove the AIR solenoid valve.
- Leave the standard hose and harness connector connected.
- Engine running, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter increases to approximately 7 kPa above BARO.
| ⇒ | 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 for a short to voltage. If the circuit tests normal, replace the ECM. |
| ⇒ | 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 ECM. |
| ⇒ | If the AIR Pressure Sensor parameter does not equal the BARO parameter, replace the AIR solenoid valve. |
| ⇒ | If not within the specified range, continue with this procedure. |
| ⇒ | If within the specified range, the AIR pump inlet hoses/pipes are restricted. Remove the restriction or replace the hose/pipe. |
| ⇒ | If not within the specified range, continue with this procedure. |
| ⇒ | If within the specified range, the AIR pump outlet hoses/pipes are restricted or leaking. Remove the restriction or replace the hose/pipe. |
| ⇒ | If less than the specified range, replace the AIR pump. |
| ⇒ | If more than the specified range, continue with this procedure. |
| ⇒ | If more than the specified range, replace the AIR solenoid valve. |
| ⇒ | If within the specified range, test/inspect the cylinder head for restriction. |
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
| • | Control Module References for control module replacement, setup, and programming |
Repair Verification
- Engine running, observe that the AIR Pressure Sensor parameter approximately equals BARO.
- 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.
- Engine running, enable the AIR solenoid with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO.
