P2258
DTC P0418, P2257, or P2258
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 Descriptors
DTC P0418
- Secondary Air Injection Pump Control Circuit
DTC P2257
- Secondary Air Injection Pump Relay Control Circuit Low Voltage
DTC P2258
- Secondary Air Injection Pump Relay Control Circuit High Voltage
Diagnostic Fault Information
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. Ignition voltage is supplied directly to the secondary air injection pump relay. The engine control module (ECM) controls the relay by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.
Conditions for Running the DTC
* The engine speed is greater than 80 RPM.
* The ignition voltage is between 10-18 V.
* The ECM has commanded the air pump relay ON and OFF at least once during the ignition cycle.
* The DTCs run continuously when the above conditions are met.
Conditions for Setting the DTC
P0418
The ECM detects the secondary air injection pump relay control circuit is open.
P2257
The ECM detects the secondary air injection pump relay control circuit is shorted to ground.
P2258
The ECM detects the secondary air injection pump relay control circuit is shorted to voltage.
Action Taken When the DTC Sets
DTC P0418, P2257, and P2258 are Type B DTCs.
Conditions for Clearing the DTC
DTC P0418, P2257, and P2258 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics (LAU) ([1][2]Electrical Diagrams)Engine Controls Schematics (LF1) ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
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: Do not run SAIR pump for more than 1-2 minutes at a time. Running for an extended period of time without allowing pump to cool may cause damage to the pump.
1. Ignition ON, command the secondary air injection pump relay ON and OFF with a scan tool. You should hear an audible click or 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. Ignition OFF, remove the KR25 secondary air injection pump relay.
2. Ignition ON, verify that a test lamp does not illuminate between the controlled output circuit terminal 30 and ground.
• If the test lamp illuminates, test the controlled output circuit for a short to voltage.
3. Verify that a test lamp illuminates between the secondary air injection pump relay coil B+ circuit terminal 86 and ground.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all components connected to the ignition circuit and replace as necessary.
4. Connect a test lamp between the control circuit terminal 85 and the secondary air injection pump relay coil B+ circuit terminal 86.
5. Command the secondary air injection pump relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
6. If all circuits test normal, test or replace the KR25 secondary air injection pump relay.
Component Testing
1. Ignition OFF, disconnect the KR25 secondary air injection pump relay.
2. Test for 70-110 ohm between terminals 85 and 86.
• If the resistance is not within the specified range, replace the KR25 secondary air injection pump relay.
3. Test for infinite resistance between the following terminals:
* 86 and 87
* 86 and 30
* 85 and 87
* 87 and 30
• If not the specified value, replace the KR25 secondary air injection pump relay.
4. Install a 20 A fused jumper wire between relay terminal 86 and B+. Install a jumper wire between relay terminal 85 and ground. Test for less than 2 ohm between terminals 87 and 30.
• If greater than the specified range, replace the KR25 secondary air injection pump relay.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning)for engine control module replacement, setup, and programming