GM Service Manual Online
For 1990-2009 cars only

Object Number: 383940  Size: MF
Engine Controls Component Views
Cell 20: EVAP and AIR
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

A voltage is directly supplied to the AIR Solenoid relay. The PCM controls the relay by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which the PCM monitors. When the PCM commands a component ON, the voltage of the control circuit should be low (near 0 volts). When the PCM commands the control circuit to a component OFF, the voltage potential of the circuit should be high (near the battery voltage). If the fault detection circuit senses a voltage other than what is expected, the fault line status changes causing the DTC to set.

The relay controls the high current flow to the AIR injection pump integral bypass valve. This allows the PCM driver to only have to control the relatively low current used by the relay.

Conditions for Running the DTC

    • The engine speed is greater than 400 RPM.
    • The system voltage is between 6 volts and 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 of the above conditions present for a minimum of 5.0 seconds.

Action Taken When the DTC Sets

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

Conditions for Clearing the MIL/DTC

    • The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Use a scan tool in order to clear the MIL and the DTC.

Diagnostic Aids

Important: 

   • Remove any debris from the PCM\TAC module connector surfaces before servicing the PCM\TAC module. Inspect the PCM\TAC module connector gaskets when diagnosing/replacing the modules. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM\TAC modules.
   • For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616 . Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.

AIR Solenoid Relay Underhood Electrical Center Terminal Identification

Front of Vehicle

Left Side of Vehicle

Ignition

Load

Right Side of Vehicle

B+

Control

    • Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed.
    • For an intermittent, refer to Symptoms .

Test Description

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

  1. Listen for an audible click when the relay operates. Be sure that both the ON and the OFF states are commanded. Repeat the commands as necessary.

  2. This test can detect a partially shorted coil which would cause excessive current flow. Leaving the circuit energized for 2 minutes allows the coil to warm up. When warm the coil may open (amps drop to 0), or short (goes above 0.75 amp).

  3. It is important to identify and test the relay coil terminals to avoid improper diagnosis.

  4. Listen for an audible click when the relay operates. Repeat the procedure as necessary.

  5. If no trouble is found in the control circuit or the connection at the PCM, the PCM may be faulty, however, this is an extremely unlikely failure.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Turn ON the ignition leaving the engine OFF.
  2. Command the AIR solenoid relay ON and OFF using the scan tool.

Does the relay turn ON and OFF when commanded?

--

Go to Step 3

Go to Step 5

3

  1. Turn OFF the ignition.
  2. Disconnect the PCM connector C2 located on the opposite side of the manufacturer's logo. Refer to Powertrain Control Module/Throttle Actuator Control Module Replacement .
  3. Turn ON the ignition leaving the engine OFF.
  4. Measure the current from the relay control circuit in the PCM harness connector to ground for 2 minutes using the DMM J 39200 on the 40 amp scale.

Important: Replace the relay if the DMM goes to 0 during the current draw test.

Does the current draw measure less than the specified value?

0.75A

Go to Diagnostic Aids

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the relay.
  3. Measure the resistance from the relay control circuit in the PCM harness connector to ground using the DMM J 39200 .

Does the DMM display infinite resistance?

--

Go to Step 12

Go to Step 10

5

  1. Turn OFF the ignition.
  2. Disconnect the relay.
  3. Connect the test lamp J 35616-200 between the AIR solenoid relay control circuit and the AIR solenoid relay ignition feed circuit at the underhood electrical center. Refer to Diagnostic Aids for terminal identification.
  4. Turn ON the ignition leaving the engine OFF.
  5. Command the relay ON and OFF using the scan tool.

Does the test lamp turn ON and OFF when commanded?

--

Go to Step 8

Go to Step 6

6

Probe the ignition feed circuit at the underhood electrical center with the test lamp J 35616-200 connected to ground. Refer to Diagnostic Aids for terminal identification.

Is the test lamp illuminated?

--

Go to Step 7

Go to Step 11

7

  1. Turn OFF the ignition.
  2. Reconnect the relay.
  3. Disconnect the PCM connector C2 located on the opposite side of the manufacturer's logo. Refer to Powertrain Control Module/Throttle Actuator Control Module Replacement .
  4. Turn ON the ignition leaving the engine OFF.
  5. With a fused jumper wire connected to ground, momentarily probe the relay control circuit in the PCM harness connector. Refer to Using Fused Jumper Wires in Wiring Systems.

Does the relay turn ON when the circuit is grounded and OFF when the circuit is opened?

--

Go to Step 9

Go to Step 10

8

  1. Inspect for poor connections at the relay. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
  2. If you find a poor connection repair the terminal as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 12

9

  1. Inspect for poor connections at the PCM. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
  2. If you find a poor connection repair the terminal as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

10

Repair the faulty relay control circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 14

--

11

Repair the faulty relay ignition feed circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 14

--

12

Replace the relay. Refer to Secondary Air Injection Solenoid Relay Replacement .

Is the action complete?

--

Go to Step 14

--

13

Important: Program the replacement PCM. Refer to Powertrain Control Module/Throttle Actuator Control Module Replacement .

Replace the PCM.

Is the action complete?

--

Go to Step 14

--

14

  1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
  2. Idle the engine at the normal operating temperature.
  3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
  4. Operate the vehicle within the Conditions for Running this DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test failed?

--

Go to Step 2

Go to Step 15

15

Select the Capture Info option and the Review Info option using the scan tool.

Does the scan tool display any DTCs that you have not diagnosed?

--

Go to the applicable DTC table

System OK