DTC 71

CODE - 71 EGR SYSTEM MALFUNCTION (ONLY FOR CALIFORNIA SPEC.)

Circuit Description




The EGR system recirculates exhaust gas, which is controlled to the proper quantity to suit the driving conditions, into the intake air mixture to slow down combustion, reduce the combustion temperature and reduces NOx emissions. The amount of EGR is regulated by the EGR vacuum modulator according to the engine load.

If even one of the following conditions is fulfilled, the VSV is turned OFF by a signal from the ECM. This results in atmospheric air acting on the EGR valve, closing the EGR valve and shutting off the exhaust gas (EGR cut-off).

Under the following conditions, EGR is cut to maintain driveability.

- Engine coolant temp. below 47°C (117°F).
- During deceleration (throttle valve closed).
- Light engine load (amount of intake air very small).
- Engine speed over 4,400 rpm.
- Engine racing.




Detecting Condition

* Refer to Trouble Code Descriptions, note *5.




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.

(1) Disconnect the EFI fuse (15 A) for 10 sec. or more, with IG switch OFF. Initiate test mode (Connect terminals TE2 and E1 of data link connector 1 with IG switch OFF).
(2) Start the engine and warm up.
(3) After the engine is warmed up, let it idle for 3 min.
(4) With the A/C ON and transmission in 5th gear (A/T in "D" position), drive at 55 ~ 60 mph (88 ~ 96 km/h) for 4 min. or less.

NOTE: If a malfunction exists, the malfunction indicator lamp will light up during step 04

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




Diagnostic Chart




Wiring Diagram

Step 1:

Step 2:

Step 3:

Step 4:

Step 5:

Step 6:

Inspection Procedure