Circuit Description
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 controlled component. 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 the PCM is expects, the fault line status changes causing the DTC to set.
The relay controls the high current flow to the AIR injection pump. 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 more than 400 RPM. |
| • | The ignition voltage is between 6.0 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 the above conditions are present for a minimum of 5 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
| • | A last test failed, or the current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic. |
| • | Use a scan tool in order to clear the MIL/DTC. |
Diagnostic Aids
Important:
• Remove any debris from the PCM connector surfaces before servicing
the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the
PCM. Ensure that the gaskets are installed correctly. The gaskets
prevent contaminate intrusion into the PCM. • For any test that requires probing the PCM or a component harness
connector, use the J 35616
connector test adapter kit. Using this kit prevents damage to
the harness/component terminals. Refer to
Using Connector Test Adapters
in Wiring Systems.
| • | The scan tool offers three modes of AIR output controls. AIR pump relay, AIR solenoid, and AIR system. |
| • | For underhood fuseblock terminal identification, refer to Electrical Center Identification Views in Wiring Systems. |
| • | For an intermittent, refer to Symptoms . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
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.
-
Tests for voltage at the coil side of the AIR pump relay.
-
Verifies that the PCM is providing ground to the AIR pump relay.
-
Tests if a ground is constantly being applied to the AIR pump relay.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||||
2 | Inspect the AIR pump fuse Is the AIR pump fuse open? | -- | ||||||||
Does the AIR pump relay turn ON and OFF with each command? | -- | |||||||||
4 |
Does the DTC reset? | -- | Go to Intermittent Conditions | |||||||
Does the test lamp illuminate? | -- | |||||||||
Does the test lamp turn ON and OFF with each command? | -- | |||||||||
Does the test lamp remain illuminated with each command? | -- | |||||||||
8 |
Did you find and correct the condition? | -- | ||||||||
9 |
Did you find and correct the condition? | -- | ||||||||
10 |
Did you find and correct the condition? | -- | ||||||||
11 |
Did you find and correct the condition? | -- | ||||||||
12 | Repair the B+ supply circuit for the AIR pump relay. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |||||||
13 | Replace the AIR pump relay. Refer to Secondary Air Injection Pump Relay Replacement . Is the action complete? | -- | -- | |||||||
14 |
Important:: Program the replacement PCM. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Is the action complete? | -- | -- | |||||||
15 |
Does this DTC reset? | -- | ||||||||
16 | With a scan tool, review the Stored information (Capture Info). Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |
