GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Corvette 🢒 Engine 🢒 Engine Controls - 5.7L 🢒 DTC P0412

Circuit Description

The secondary air injection (AIR) solenoid is used as a switch to 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 engine vacuum to open the shut-off valve. The PCM driver monitors the control circuit 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.

Conditions for Running the DTC
    • The engine speed is more than 400 RPM.
    • The system voltage is between 6-18 volts.

Conditions for Setting the DTC
    • The PCM detects that the commanded state of the driver and the actual state of the control circuit do not match.
    • All the above conditions exist for a minimum of 5 seconds.

Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests for voltage to the AIR solenoid valve.

    2.

  2. This step verifies that the PCM is providing ground to the AIR solenoid valve.

    3.

  3. 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

Go to Diagnostic System Check - Engine Controls

2

Are DTCs P0102, P0418, P0443, P0449, P0740, P0785, P1860 also set?

Go to Step 12

Go to Step 3

3
  1. Turn ON the ignition, with the engine OFF.
  2. Command the AIR solenoid valve ON and OFF with a scan tool.
  3. Listen for a click at the rear of the right front fender when the AIR solenoid operates. Repeat commands as necessary.

Does the AIR solenoid valve turn ON and OFF when commanded with a scan tool?

Go to Step 4

Go to Step 5

4

  1. Review the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Does this DTC set?

Go to Step 5

Go to Intermittent Conditions

5

  1. Turn OFF the ignition.
  2. Disconnect the AIR solenoid valve.
  3. Turn ON the ignition, with the ignition OFF.
  4. Probe the ignition 1 voltage circuit of the AIR solenoid with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

Go to Step 6

Go to Step 13

6

  1. Connect a test lamp between the control circuit of the AIR solenoid and the ignition 1 voltage circuit of the AIR solenoid.
  2. Command the AIR solenoid valve ON and OFF with a scan tool

Does the test lamp turn ON and OFF with each command?

Go to Step 10

Go to Step 7

7

Does the test lamp remain illuminated with each command of the scan tool?

Go to Step 9

Go to Step 8

8

Test the control circuit of the AIR solenoid for an open circuit or for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 11

9

Test the control circuit of the AIR solenoid 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

10

Test for an intermittent and for a poor correction at the AIR solenoid valve. 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

11

Test for an intermittent and for a poor correction 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

12
  1. Repair the short to ground in the ignition 1 voltage circuit or related components. Refer to Wiring Repairs and Circuit Testing in Wiring Systems.
  2. Replace the ENG ING 1 fuse as necessary.

Did you complete the repair?

Go to Step 16

--

13

Repair the open 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
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

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?

Go to Diagnostic Trouble Code (DTC) List

System OK