Diagnostic Trouble Code

Locations And Wiring Basic Schematic:

SYSTEM/WIRING DIAGRAM

SYSTEM DESCRIPTION
Exhaust oxygen concentration at the upper part and the lower part of TWC is detected from HO2S-1 and HO2S-2 respectively and accordingly ECM (PCM) controls the closed loop which then controls the fuel injection volume. While the above control is going on and if TWC is in good condition, the output voltage of HO2S-2 is maintained at specified level. As TWC is in becomes deteriorated, even when the above control is going on, the exhaust gas which has passed TWC then passes HO2S-2 at the exhaust oxygen concentration similar to that of the upper part of TWC without being oxygenated or converted. Thus, wave forms of HO2S-1 and HO2S-2 output voltage become alike. ECM (PCM) judges deterioration of TWC by comparing wave forms of HO2S-1 and HO2S-2.




DTC DETECTING CONDITION AND TROUBLE AREA

DTC CONFIRMATION PROCEDURE

NOTE: Check to make sure that following conditions are satisfied when using this DTC CONFIRMATION PROCEDURE.

WARNING:
- When performing a road test, select a place where there is no traffic or possibility of a traffic accident and very careful during to avoid occurrence of an accident.
- Road test, should be carried out with 2 person, a driver and tester, on a level road.

- Intake air temperature: between -14°C and 70°C (6.8°F and 158°F)
- Atmospheric pressure: higher than 560 mm.Hg (Altitude: lower than 2790 m 9150 ft))
- Following DTCs are not detected: P0101, P0102, P0103, P0111, P0112, P0113, P0116, P0117, P0118, P0131, P0132, P0133, P0134, P0135, P0136, P0141, P0335, P0461, P0463, P0500, P1450 and P1451

1. With ignition switch OFF connect scan tool.
2. Turn ON ignition switch and clear DTC by using scan tool if any.
3. Start engine and warm up to normal operating temperature.
4. Increase vehicle speed to 56 kmh (35 mph) or more.
5. Keep above vehicle speed for 5 min. (Throttle valve operating is kept constant in this step.)
6. Increase vehicle speed to 80 - 100 kmh (50 - 60 mph). (engine speed; 2500 - 3000 rpm.)
7. Keep above vehicle speed for 1 min. (Throttle valve operating is kept constant in this step.)
8. Stop vehicle and check DTC and pending DTC by using scan tool.




DTC TROUBLESHOOTING