P2444
DTC P2444
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC P2444
- Secondary Air Injection System Pump Stuck ON
Circuit/System Description
The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A pressure sensor is used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5-volt reference circuit and supplies a ground to the low reference circuit. The sensor provides a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.
Ignition voltage is supplied to the secondary air injection pump and air injection shutoff/check valve relay. The ECM controls the relay by grounding the control circuit, which activates the relay. When the relay contact closes, voltage is supplied to the pump and the valve, which turns the pump on and opens the valve.
The diagnostic uses 3 phases to test the secondary air injection 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 secondary air injection pump and the secondary air injection shutoff and check valve is activated. Normal secondary air function occurs. Expected system pressure is 6-14 kPa (0.9-2.0 psi) above BARO. Relatively high magnitude of pressure pulses are expected due to exhaust pulses. Low magnitude pressure pulses indicate a blockage or disconnect downstream of the valve.
During phase 2, only the secondary air injection pump is activated. The shutoff and check valve is closed. Pressure sensor performance and shutoff and check valve deactivation are tested. Expected system pressure is 18-28 kPa (2.6-4.0 psi) above BARO.
During phase 3, neither the secondary air injection pump nor the secondary air injection shutoff and check valve is activated. Secondary air injection pump deactivation is tested. Expected system pressure equals BARO.
Conditions for Running the DTC
* DTC P0101-P0103, P0106-P0108, P0111-P0114, P0116-P0118, P0121-P0123, P0128, P0201-P0204, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300-P0304, P0351-P0354, P0412, P0418, P0420, P0606, P0641, P0651, or P2430-P2433 is not set.
* The engine has been OFF for greater than 10 s.
* The ignition voltage is greater than 10 V.
* The engine speed is less than 3,000 RPM.
* The intake air temperature (IAT) is greater than -12°C (+10°F).
* The engine coolant temperature (ECT) is between -12 and +38°C (10-100°F).
* The barometric pressure (BARO) is greater than 60 kPa (8.7 psi).
* The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
* The mass air flow (MAF) is less than 50 g/s.
* The secondary air injection pump is commanded ON.
* Phase 1 and phase 2 of the secondary air injection system test have run and passed.
* DTC P2444 runs once per ignition cycle when the above conditions are met for greater than 4 s.
Conditions for Setting the DTC
The ECM detects that average difference between the predicted system pressure and the actual system pressure is greater than or less than calibrated thresholds for greater than 2 s.
Action Taken When the DTC Sets
DTC P2444 is a Type A DTC.
Conditions for Clearing the MIL/DTC
DTC P2444 is a Type A DTC.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
Description and Operation
Secondary Air Injection System Description Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Circuit/System Verification
Note: To prevent the secondary air injection pump from overheating, do not operate the pump consecutively for greater than 2 minutes. The pump is provided with a thermal protector that will automatically reset when allowed to cool.
1. Command the Secondary Air Injection Pump Relay ON and OFF with a scan tool. The secondary air injection pump should turn ON and OFF.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Vehicle OFF, disconnect the harness connector at the G21 secondary air injection pump.
2. Vehicle in Service Mode, verify that a test lamp does not illuminate between the G21 secondary air injection pump control circuit terminal 1 and ground.
• If the test lamp illuminates, test the control circuit for a short to voltage.
3. If the circuit tests normal replace the KR25 secondary air injection pump relay.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)
* Secondary Air Injection Pump Replacement Service and Repair