For Diagnosis refer to Engine Controls Schematics .
Circuit Description
The PCM activates the secondary air injection system by grounding the AIR relay. This energizes the pump and the vacuum control solenoid. As vacuum is applied to the two shutoff valves, fresh air is allowed to pass through them. The AIR pump forces fresh air past the shutoff valves and into the exhaust stream in order to accelerate catalyst operation. The PCM will run up to 3 diagnostic tests using the O2S1 voltage and Short Term FT to verify system operation. The system can be diagnosed during normal secondary air injection operation or the scan tool can activate the system specifically for diagnostic purposes. If an air flow problem is detected this DTC will set. When inactive, the shutoff valve prevents air flow in either direction.
Conditions for Running the DTC
| • | AIR system commanded ON for more than 20 seconds. |
| • | The IAT is between 1° C and 151° C (32° F and 302° F). |
| • | The ECT is between 5° C and 114° C ( 41° F and 230° F). |
| • | Battery voltage is more than 11.7 volts. |
| • | Engine run time is more than 200 seconds. |
| • | Calculated air flow is more than 11 gps. |
| • | Accumulated flow between 240 cts and 600 cts. |
| • | BLM cell of 16 or 17. |
| • | TPS changes less than 5 percent. |
| • | Stabilization time of more than 1 second. |
| • | Fuel ethanol composition of less than 15 percent. |
| • | DTCs 105, 107, 108, 112, 113, 117, 118, 122, 123, 130, 131, 132, 133, 1133, 134, 171, 172, 178, 179, 201, 202, 203, 204, 300, 336, 340, 341, 506, 507, 601, 602, and 1621 are not set. |
Conditions for Setting the DTC
Lean time is more than 1 second during 4 second active test.
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) illuminates after two ignition cycles with the malfunction present. |
| • | The PCM records the operating conditions at the time the diagnostic fails. The Freeze Frame and Failure Records buffers stores this information. |
| • | A history DTC is stored. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn OFF after 3 consecutive ignition cycles in which the diagnostic runs without a fault. |
| • | A history DTC will clear after 40 consecutive warm up cycles without a fault. |
| • | A scan tool can clear the DTCs. |
Diagnostic Aids
An intermittent may be caused by any of the following conditions:
| • | A poor connection |
| • | Rubbed through wire insulation |
| • | A broken wire inside the insulation |
Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step checks for a restriction in the engine vacuum supply to the AIR shutoff valve.
-
This step determines if the lack of air is caused by an open in the AIR supply hose or a defective shutoff valve.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 | Start the engine. Does the AIR pump run constantly? | -- | ||
3 |
Is the test lamp illuminated? | -- | ||
4 |
Does the AIR pump turn ON? | -- | ||
5 |
Is the test lamp illuminated? | -- | ||
6 | Probe the AIR pump relay B+ supply circuit terminal (control side of relay) using the test lamp connected to ground. Is the test lamp illuminated? | -- | ||
7 |
Is the test lamp illuminated? | -- | ||
8 |
Is the test lamp illuminated? | -- | ||
9 |
Is the test lamp illuminated? | -- | ||
10 | Probe terminal B of the C2 connector with a test lamp connected to B+. Is the test lamp illuminated? | -- | ||
11 |
Does the Short Term FT increase by the minimum specified amount in the time given? | 12% in 6 seconds | Go to Diagnostic Aids | |
12 |
Is the test lamp illuminated? | -- | ||
13 |
Is the test lamp illuminated? | -- | ||
Is near engine idle vacuum displayed on the vacuum gauge? | -- | |||
Is air pressure from the AIR pump present at the AIR hose outlet? | -- | Go to Diagnostic Aids | Go to Step 16 | |
16 |
Is air pressure present at the outlet of the AIR shut-off valve? | -- | ||
17 | Repair the short to ground in the AIR relay control circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
18 | Repair the open circuit or short to ground between the battery supply and the AIR relay. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
19 | Repair the faulty ground connection or the open ground circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
20 | Repair the open circuit between the IGN E fuse and the AIR pump relay. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
21 | Repair the open in the relay control circuit between the PCM and the relay. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
22 |
Is the reading within the specification? | 0 - 2 ohms | ||
23 | Replace the AIR pump relay. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
24 | Repair the open in the battery supply from the AIR relay to the AIR pump/solenoid. Refer to Wiring Repairs in Wiring systems. Is the action complete? | -- | -- | |
25 |
Did you find and correct the condition? | -- | ||
26 |
Important: Inspect the vacuum check valve for proper installation. The tapered side of the check valve goes toward the vacuum source. Also inspect for vacuum with the check valve removed from the vacuum line. If there is vacuum replace the check valve. If vacuum is present to the solenoid, replace the AIR solenoid. Repair the vacuum restriction to the AIR shutoff valve. Is the action complete? | -- | -- | |
27 | Repair the open/restriction in the AIR hose between the AIR pump shutoff valve and the AIR exhaust check valve. Is the action complete? | -- | -- | |
28 | Check for a restriction in the AIR intake hose. If no restriction is found, replace the AIR shut-off valve. Is the action complete? | -- | -- | |
29 | Replace the AIR pump. Refer to Secondary Air Injection Pump Replacement . Is the action complete? | -- | -- | |
30 |
Does the scan tool indicate that this test Passed? | -- | ||
31 | Select the capture Info option and the review info option using the scan tool. Are any DTCs displayed that you have not diagnosed? | -- | Go to applicable DTC table | System OK |
