DTC 27

DTC 27 Sub Heated Oxygen Sensor Circuit

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





DETECTING CONDITION

DIAGNOSTIC TROUBLE CODE DETECTION DRIVING PATTERN

Purpose of the driving pattern.
(a) To simulate diagnostic trouble code detecting condition after diagnostic trouble code is recorded.
(b) To check that the malfunction is corrected when the repair is completed confirming that diagnostic trouble code is no longer detected.

Detection Driving Pattern:

Malfunction: Open or Short in Sub Heated Oxygen Sensor

(1) Disconnect the EFI No.1 fuse (30A) for 10 sec. or more, with IG switch OFF. Initiate test mode (Connect terminal TE2 and E1 of data link connector 2 with IG switch OFF).
(2) Start the engine and warm up with all ACC switched OFF.
(3) Drive the vehicle at 80 ~ 88km/h (50 ~ 55mph) for 10 min. or more.
(4) Stop at a safe place and idle the engine for 2 min. or less.
(5) Accelerate to 96 km/h (60 mph) with the throttle valve fully open.

HINT: If a malfunction exists, the malfunction indicator 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.





WIRING DIAGRAM

Step 1:

Step 2:

Step 3:

Step 4:

INSPECTION PROCEDURE

HINT: When other codes are output in addition to 27 at the same time, check the circuits for other codes first.