DTC 71

CIRCUIT DESCRIPTION
The EGR system is designed to recirculate the exhaust gas properly controlled according to the driving condition back into the intake air-fuel mixture. It helps to slow down combustion in the cylinder and thus lower the combustion temperature which, in turn, reduces the amount of NOx emission. 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 switched ON by a signal from the ECM. This resuits in atmospheric air acting on the EGR valve, closing the EGR valve and shutting off the exhaust gas (EGR cut-OFF).
- Engine coolant temp. below 5O°C (122°F)
- During deceleration (throttle valve closed)
- Light engine load (amount of intake air very small)
- Engine speed over 5,200 rpm
- Traction control is operating.





DETECTING CONDITION AND TROUBLE AREA

DIAGNOSIS TROUBLE CODE DETECTION DRIVING PATTERN:

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.





Malfunction: Open in EGR Gas Temp. Sensor Circuit.

1. Remove EFI fuse (30 A) for 10 seconds or more, with ignition switched OFF. Initiate test mode (Connect terminals TE2 and E1 of data link connector 2 with ignition switched OFF).
2. Start engine and warm up.
3. Let engine idle for 3 minutes.
4. With A/C switched ON and transmission in in 5th gear (A/T in 3rd speed) drive at 88 - 96 km/h (55 - 60 mph) for 4 minutes or less.

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

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





DIAGNOSTIC CHART





WIRING DIAGRAM




















INSPECTION PROCEDURE