The secondary air injection (AIR) vacuum control solenoid is used as a switch to direct and control engine vacuum to the AIR shut-off valve.
Voltage is supplied to the AIR solenoid by the ignition 1 voltage circuit. The powertrain control module (PCM) commands the AIR solenoid ON by supplying a ground on the control circuit by an internal switch called a driver. This action completes the circuit and energizes the AIR solenoid allowing vacuum to open the shut-off valve. The PCM driver monitors the control circuit voltage constantly for proper voltage conditions. When the PCM commands the AIR solenoid ON, the circuit voltage should be low, near 0 volts. When the PCM commands the control circuit OFF, the voltage potential of the circuit should be high, near the battery voltage. If the PCM detects a voltage other than what is expected, DTC P0412 sets.
• | The engine is running. |
• | The system voltage is between 8-16 volts. |
• | The PCM detects an improper voltage level on the control circuit of the AIR vacuum control solenoid valve. |
• | The condition exists for at least 10 seconds. |
• | The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails. |
• | The PCM stores the conditions present when the DTC set as Freeze Frame/Failure Records data. |
• | The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes. |
• | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
• | The DTC can be cleared by using the scan tool Clear DTC Information function. |
The numbers below refer to the step numbers on the diagnostic table.
This step tests for voltage to the AIR solenoid valve.
This step verifies that the PCM is providing ground to the AIR solenoid valve.
This step tests if a ground is constantly being applied to the AIR solenoid valve.
Step | Action | Yes | No | ||||
---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | |||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |||||
2 | Is DTC P0102, P0418, or P0443 set? | Go to Step 3 | Go to Step 4 | ||||
3 |
Did you find and correct the condition? | Go to Step 16 | Go to Inducing Intermittent Fault Conditions in Wiring Systems | ||||
4 |
Does the AIR solenoid valve turn ON and OFF with each command? | Go to Step 5 | Go to Step 6 | ||||
5 |
Does the DTC reset? | Go to Step 6 | Go to Intermittent Conditions | ||||
Does the test lamp illuminate? | Go to Step 7 | Go to Step 13 | |||||
Does the test lamp turn ON and OFF when commanded with a scan tool? | Go to Step 11 | Go to Step 8 | |||||
Does the test lamp remain illuminated with each command? | Go to Step 10 | Go to Step 9 | |||||
9 | Test the AIR solenoid control circuit for a short to voltage an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 12 | ||||
10 | Test the control circuit between the AIR solenoid valve and the PCM for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 15 | ||||
11 | Test for an intermittent and for a poor connection at the AIR vacuum solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 14 | ||||
12 | Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 15 | ||||
13 | Repair the open or high resistance in the ignition 1 voltage circuit . Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 16 | -- | ||||
14 | Replace the AIR solenoid valve. Refer to Secondary Air Injection Vacuum Control Solenoid Valve Replacement . Did you complete the replacement? | Go to Step 16 | -- | ||||
15 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | Go to Step 16 | -- | ||||
16 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 17 | ||||
17 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK |