P2444

DTC P2444

System Description

The DTC P2444 Secondary Air Injection (AIR) System Pump Stuck On diagnostic monitors the AIR pump activity. The secondary AIR system helps reduce exhaust emissions. 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 shut-off valve. The AIR shut-off valve controls the flow of air from the AIR pump to the exhaust manifold. The AIR solenoid valve supplies the manifold vacuum that is used to operate the AIR shut-off valve. A pressure sensor is used to monitor the air flow from the AIR pump. By comparing the measured pressure against the expected pressure the pressure sensor can detect faults in the AIR pump, AIR shut-off valve, and the AIR solenoid valve. The pressure sensor can also detect leaks in the secondary AIR system plumbing.

Conditions for Running the DTC

* The engine is running.
* DTC P2444 runs continuously once the above condition has been met.

Conditions for Setting the DTC

The pressure sensor detects air flow even when the AIR pump is commanded OFF.

Action Taken When the DTC Sets

* The PCM illuminates the malfunction indicator lamp (MIL) during the second key cycle in which the diagnostic trouble code (DTC) sets.
* The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC

* The PCM turns OFF the MIL on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present.
* A DTC will clear after 40 consecutive warm-up cycles have occurred without a fault.
* A DTC can be cleared by using the scan tool Clear Information function.

Diagnostic Aids

Inspect for any of the following conditions:

* The resistance of the AIR pump relay-The resistance across terminal 1 and terminal 2 is 85-95 ohms at 20°C (68°F). The resistance across terminal 3 and terminal 4 is infinite.
* The AIR pump relays electrical contacts may be pitted and sticking. Replace the relay if tapping gently on the relay or wiggling the relay causes a change in the relays operation.
* The performance of the AIR pump relay may be affected by temperature. Check the relay after sitting outside overnight and after running the engine 30 minutes.
* An intermittent malfunction may be caused by a fault in an AIR system electrical circuit. Inspect the wiring harness and components for an intermittent condition. Refer to Intermittent Conditions (Intermittent Conditions).

Test Description

The numbers below refer to the step numbers on the diagnostic table.
1. The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
3. This step checks for the correct operation of the AIR pump.
4. This step checks for the correct operation of the AIR pump relay.