P2430

DTC P2430 (WITH RPO CODE NU3)

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 AIR 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:
- DTCs P0411 and P2430 run during Phase 1
- DTCs P2430 and P2440 run during Phase 2
- DTC P2444 runs during Phase 3

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.

DTC P2430-The AIR system pressure sensor is stuck range diagnostic monitors the amount of change in the sensor signal during phase 1 and phase 2. When the PCM detects AIR pressure sensor signal change is less than expected DTC P2430 sets. DTC P2430 runs during phase 1 and phase 2.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P2430 Secondary Air Injection (AIR) System Pressure Sensor Stuck in Range

CONDITIONS FOR RUNNING THE DTC
- DTCs P0412, P0418, P0606, P0641, P0651, P2432, P2433 are not set.
- The system voltage is between 10-18 volts.
- The engine is running.
- The start-up engine coolant temperature (ECT) is between 5-50°C (41-122°F).
- The start-up intake air temperature (IAT) is between 5-60°C (41-140°F).
- The BARO parameter is more than 60 kPa.
- The MAF sensor parameter is between 3-24 g/s.
- DTC P2430 runs once per trip start up when the above conditions are met and AIR pump operation is requested.

CONDITIONS FOR SETTING THE DTC
- The measured AIR pressure change does not meet expected pressure changes during AIR pump phase 1 or phase 2 operation.
- DTC P2430 sets with in 8 seconds when the above conditions are met.

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.

DIAGNOSTIC AIDS
- An intermittent malfunction may be caused by a fault in an AIR control/shut-off valve assembly pressure sensor electrical circuits. Inspect the wiring harness and components for an intermittent condition.
- If the DTC cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC was first set.

TEST DESCRIPTION

Step 1 - Step 7:

Step 8 - Step 16:

Step 17 - Step 25:

The numbers below refer to the step numbers on the diagnostic table.
5. DTC P2444 will locate and repair the cause of an AIR pump stuck in the ON position.
6. Normal pressure sensor input voltage is approximately 2.6 volts with the ignition ON, the engine OFF, and the AIR pump OFF.
13. This step places a known load in the circuit in order to verify proper voltage drop. An appropriate length of secondary ignition wire may be adequate for a fixed 300 ohm resistor.
15. The low reference, the AIR pressure signal, the 5-volt reference circuits and the PCM have tested OK. Replace the AIR control solenoid valve/pressure sensor assembly.