Operation CHARM: Car repair manuals for everyone.
Home >> Chevrolet >> 2006 >> TrailBlazer 4WD L6-4.2L VIN S >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P2432

P2432



DTC P2432

DTC DESCRIPTOR

DTC P2432
Secondary Air Injection System Pressure Sensor A Circuit Low

DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection






TYPICAL SCAN TOOL DATA

AIR Pressure Sensor:






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 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 control module 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

In all 3 phases, testing is accomplished by comparing the measured pressure against the expected pressure. The control module 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
- DTCs P0606, P1635, P1639 are not set.
- The ignition is ON or the engine is running.
- DTC P2432 runs continuously when the above conditions are met.

CONDITIONS FOR SETTING THE DTC
The pressure sensor signal is less than 0.2 volt for at least 12.5 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

CIRCUIT/SYSTEM VERIFICATION
Engine running, observe that the AIR Pressure Sensor parameter approximately equals BARO.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the harness connector at the AIR solenoid valve.
2. Ignition OFF, test for less than 1.0 ohm of resistance between the low reference circuit terminal 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 control module.
3. Ignition ON, test for 4.8 - 5.2 volts between the 5-volt reference circuit terminal 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 control module.
- If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module.
4. Verify the scan tool AIR Pressure Sensor parameter is less than 0.5 volts.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the control module.
5. Install a 3-amp fused jumper wire between the signal circuit terminal and the 5-volt reference circuit terminal. 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 short to ground or an open/high resistance. If the circuit tests normal, replace the control module.
6. If all circuits test normal, test or replace the AIR solenoid valve.

COMPONENT TESTING

Solenoid Valve
1. Apply fused battery voltage and ground to the solenoid and verify that the valve opens and closes completely as voltage is applied to and removed from the solenoid. Observe that the valve is not obstructed or leaking.
- If the valve operates incorrectly, leaks, or is obstructed, remove the obstruction or replace the valve.

REPAIR INSTRUCTIONS
- Secondary Air Injection (AIR) Pump Replacement
- Secondary Air Injection (AIR) Solenoid Valve Replacement
- Secondary Air Injection (AIR) Pipe Replacement
- Control Module References for control module replacement, setup and programming

REPAIR VERIFICATION
With the 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.
pro multis · About Operation CHARM