DTC 71

Code 71 Description:

Data Trouble Code No. 71 - Exhaust Gas Recirculation System Malfunction

Detecting Condition
Exhaust Gas Recirculation Gas Temperature is 75°C (167°F) or below for 1 - 4 minutes under the following conditions (2 trip detection);
- Engine coolant temperature 65°C (149°F) or more.
- Exhaust Gas Recirculation operation possible i.e., automatic transmission in 3rd gear, A/C ON, 96 km/h (60 mph), flat road.

Trouble Area
- Open in Exhaust Gas Recirculation Gas Temperature Sensor circuit.
- Engine Control Module.

Malfunction Indicator Lamp
Normal Mode ON
Test Mode ON

Circuit Description
The exhaust gas recirculation 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 reduce NOx emissions.

The lift amount of the exhaust gas recirculation valve is controlled by a step motor operated by the engine control module. The engine control module operates the motor only a preprogrammed amount in response to the engine operating conditions (engine rpm, intake air volume to adjust the exhaust gas recirculation volume to the target value.)

Under the following conditions, exhaust gas recirculation is cut to maintain driveabilitv.
^ Engine coolant temp. below 53°C (127°F)
^ During deceleration (throttle valve closed)
^ Light engine load (amount of intake air very small)
^ Engine speed over 4,000 rpm
^ Engine Idling
^ Park/neutral position switch on