Description

DATA TROUBLE CODE: 27

SYSTEM: Sub Oxygen Sensor Circuit

WIRING DIAGRAM




CIRCUIT DESCRIPTION
The sub oxygen sensor is installed on the exhaust pipe. Its construction and operation is the same as the main oxygen sensor.

DIAGNOSTIC TROUBLE CODE DETECTING CONDITION
- Main oxygen sensor signal is 0.45 volts or more and sub oxygen sensor signal is 0.45 volts or less under conditions (a) and (c). (2 trip detection logic)
Monitors, Trips, Drive Cycles and Readiness Codes
(a) Engine coolant temperature : 80°C (176°F) or more.
(b) Engine speed: 1,500 rpm or more.
(c) Accelerator pedal: Fully depressed for 2 seconds or more

TROUBLE AREA
- Open or short in sub oxygen sensor circuit.
- Sub oxygen sensor.
- ECM.

DIAGNOSTIC TROUBLE CODE DETECTION DRIVING PATTERN
Malfunction: Open or Short in Sub Oxygen Sensor.
- Purpose of the driving pattern:
- To simulate diagnostic trouble code detecting condition after diagnostic trouble code is recorded.
- To check that the malfunction is corrected when the repair is completed confirming that diagnostic trouble code is no longer detected.




(1) Disconnect the EFI (15 A) fuse for 10 sec. or more, with ignition switch OFF. Initiate test mode (Connect terminals TE2 and E1 of data link connector 1 (DLC1) with ignition switch OFF).

(2) Start the engine and warm up, with all accessories switched OFF.

(3) After the engine is warmed up, let it drive at 50 ~ 55 mph (80 ~ 88 km/h) for 10 minutes or more.

(4) After driving, stop at a safe place and perform idling for 2 minutes or less.

(5) After performing the idling in (4) , perform acceleration to 60 mph (96 km/h) with the throttle valve fully open.

HINT: If a malfunction exists, the Malfunction Indicator Lamp ("CHECK" engine lamp) will light up during step (5).

NOTICE; If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.