Note. For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .
Circuit Description
Secondary Air Injection (AIR) system is used to lower tailpipe emissions during start up. PCM supplies ground to AIR pump relay, energizing pump.
PCM runs 2 tests using HO2S voltages to diagnose AIR system. tests consist of
- Test I PCM monitors HO2S voltage when AIR pump is enabled. If HO2S voltage drops to a predetermined range, PCM assumes that AIR pump is operational. If HO2S voltage increases to a predetermined range, PCM assumes that AIR pump is disabled. If HO2S voltages are out of range or inconclusive, diagnostic will proceed to next test.
- Test II During this test, PCM will activate AIR pump during "closed loop" operation. When AIR is activated, PCM will monitor HO2S voltages and short term trim values for both banks of engine. If PCM determines that HO2S voltages for both banks does not respond as expected during tests, DTC P0410 will set. If only one sensor responded, PCM will set either a DTC P1415 or P1416 to indicate which bank AIR system is inoperative.
DTC will set when following conditions are present
- DTCs P0107, P0108, P0116, P0117, P0118, P0133, P0135, P0153, P0155, P0171, P0172, P0174 or P0175 not set.
- Engine operating for 2 seconds.