P0418
DTC P0412 or P0418
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 P0412
- Secondary Air Injection Valve Control Circuit
DTC P0418
- Secondary Air Injection Pump Relay Control Circuit
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 and secondary air solenoid valve relay. The engine control module (ECM) controls the relays by grounding the control circuit with a solid state device called a driver. The ECM monitors the control circuits for open, short to ground, or short to voltage conditions.
Conditions for Running the DTC
* The ignition voltage is between 10-32 V.
* The DTCs run continuously once the above conditions are met.
Conditions for Setting the DTC
DTC P0412 or P0418
The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 s.
Action Taken When the DTC Sets
DTC P0412, and P0418 are Type B DTCs.
Conditions for Clearing the DTC
DTC P0412, and P0418 are Type B DTCs.
Diagnostic Aids
If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool Secondary Air Injection Solenoid Valve Control Circuit and Secondary Air Injection Pump Relay Control Circuit Test Status parameters. The circuit status parameter changes from OK or Not Run to Malfunction if there is a condition with the circuit or a connection.
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
1. Vehicle in Service Mode, command the Secondary Air Injection System between Inactive and Active with a scan tool. You should hear or feel a click from the KR25 secondary air injection pump relay and the KR26 secondary air injection solenoid valve relay.
2. Command the Secondary Air Injection System between Inactive and Active with a scan tool while observing the following circuit status parameters:
* Secondary Air Injection Pump Relay Control Circuit Low Voltage Test Status
* Secondary Air Injection Pump Relay Control Circuit Open Test Status
* Secondary Air Injection Pump Relay Control Circuit High Voltage Test Status
* Secondary Air Injection Solenoid Valve Control Circuit Low Voltage Test Status
* Secondary Air Injection Solenoid Valve Control Circuit Open Test Status
* Secondary Air Injection Solenoid Valve Control Circuit High Voltage Test Status
Each parameter should toggle between OK and Not Run.
3. 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
P0412
1. Vehicle OFF, disconnect the KR26 secondary air injection solenoid valve relay.
2. Vehicle in Service Mode, verify that a test lamp illuminates between the relay coil ignition circuit terminal 85 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 or replace the KR26 secondary air injection solenoid valve relay.
3. Verify a test lamp does not illuminate between the ignition circuit terminal 85 and the control circuit terminal 86.
• If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module.
4. Remove the test lamp.
5. Command the Secondary Air Injection Solenoid Valve Open with a scan tool. Verify the scan tool Secondary Air Injection Solenoid Valve Control Circuit High Voltage Test Status Parameter is OK.
• If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
6. Install a 3 A fused jumper wire between the control circuit terminal 86 and the ignition circuit terminal 85. Command the Secondary Air Injection Solenoid Valve Open with a scan tool. Verify the scan tool Secondary Air Injection Solenoid Valve Control Circuit High Voltage Test Status Parameter is Malfunction.
• If not the specified value, test the control circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
7. If all circuits test normal, test or replace the KR26 secondary air injection solenoid valve relay.
P0418
1. Vehicle OFF, disconnect the KR25 secondary air injection pump relay.
2. Vehicle in Service Mode, verify that a test lamp illuminates between the relay coil B+ circuit terminal 85 and ground.
• If the test lamp does not illuminate, repair the open/high resistance in the circuit.
3. Verify a test lamp does not illuminate between the B+ circuit terminal 85 and the control circuit terminal 86.
• If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module.
4. Remove the test lamp.
5. Command the Secondary Air Injection Pump Relay ON with a scan tool. Verify the scan tool Secondary Air Injection Pump Relay Control Circuit High Voltage Test Status Parameter is OK.
• If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
6. Install a 3 A fused jumper wire between the control circuit terminal 86 and the B+ circuit terminal 85. Command the Secondary Air Injection Pump Relay ON with a scan tool. Verify the scan tool Secondary Air Injection Pump Relay Control Circuit High Voltage Test Status Parameter is Malfunction.
• If not the specified value, test the control circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
7. If all circuits test normal, test or replace the KR25 secondary air injection pump relay.
Component Testing
Relay Test
1. Vehicle OFF, disconnect the appropriate relay.
2. Test for 70-110 ohms between terminals 85-86.
• If not within the specified range
Replace the relay.
• If within the specified range
3. Test for infinite resistance between the terminals listed below:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
• If less than infinite resistance
Replace the relay.
• If infinite resistance
4. Install a 15 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground.
5. Test for less than 2 ohms between terminals 30 and 87.
• If 2 ohms or greater
Replace the relay.
• If less than 2 ohms
6. All OK
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)
* Control Module References Programming and Relearning for Engine Control Module replacement, programming, and setup