Circuit Description
A voltage is directly supplied to the AIR pump relay coil. 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 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 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 Pump Relay Terminal Identification | |||
|---|---|---|---|
Front of Vehicle | |||
Left Side of Vehicle | Ignition | B+ | Right Side of Vehicle |
Load | Control | ||
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. Command both the ON and the OFF states. Repeat the commands as necessary.
-
This step tests for voltage at the coil side of the relay.
-
This step verifies that the PCM is providing ground to the AIR pump relay.
-
This step tests if a ground is constantly being applied to the AIR pump relay.
-
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.
-
This DTC will not report a pass. The scan tool status for this DTC will never report a pass. The scan tool will only display when the diagnostic fails. The repair is not complete if the scan tool indicates that the diagnostic ran and failed.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
Does the relay turn ON and OFF with each command? | -- | |||
3 |
Does this DTC reset? | -- | Go to Intermittent Conditions | |
Does the test lamp illuminate? | -- | |||
Does the test lamp turn ON and OFF with each command? | -- | |||
6 | Does the test lamp remain illuminated with each command? | -- | ||
Did you find and correct the condition? | -- | |||
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 | Repair the coil side feed circuit of the AIR pump relay. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
12 | Replace the relay. Refer to Secondary Air Injection Pump Relay Replacement . Is the action complete? | -- | -- | |
|
Important: Program the replacement PCM. Replace the PCM. Refer to Powertrain Control Module Replacement . Is the action complete? | -- | -- | ||
Does the DTC reset? | -- | |||
15 | With a scan tool, review the Stored information (Capture Info). Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to the applicable DTC table | System OK |
