DTC 0305

EGR Temperature Sensor (DTC: 0305)










DESCRIPTION
The EGR temperature sensor detects temperature changes in the EGR passage way. When the EGR valve opens, hot exhaust gases flow, and the temperature in the passage way changes. The EGR temperature sensor is a thermistor that modifies a voltage signal sent from the ECM. This modified signal then returns to the ECM as an input signal. As the temperature increases, EGR temperature sensor resistance decreases.
This sensor is not used to control the engine system. It is used only for the on board diagnosis.




DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE

OVERALL FUNCTION CHECK
Use this procedure to check the overall function of the EGR temperature sensor. During this check, a DTC might not be confirmed.

Procedure for malfunctions A and B
With Consult
1) Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT.




2) Confirm that engine coolant temperature and intake air temperature are lower than 40°C (104°F). (If necessary, wait until the temperatures equal atmospheric temperature.)
3) Confirm that "EGR TEMP SEN" reading is between 3.0V and 5.0V.
4) Start engine and warm it up sufficiently.
5) Run engine at idle for at least 2 minutes.




6) Confirm that EGR valve is not lifting. (If necessary, try lifting with a suitable tool.) If NG, go to TROUBLE DIAGNOSES FOR DTC P0400.
7) Read "EGR TEMP SEN" at about 1,500 rpm with EGR valve lifted up to the full position using a suitable tool. (When lifting up, place the tool as near to valve center as possible. Also, take care not to damage diaphragm.)
Voltage should decrease to less than 1.0V.
8) If step 7 is OK, perform TROUBLE DIAGNOSES FOR DTC P0400 and P1400.

OR

Without Scan Tools
1) Turn ignition switch "ON".




2) Confirm that voltage between ECM terminals (59), (60) and ground are more than 2.72V. (It necessary, wait until engine coolant temperature and intake air temperature equal atmospheric temperature.)




3) Confirm that voltage between ECM terminal (63) and ground is between 3.0V and 5.0V.
4) Start engine and warm it up sufficiently.
5) Run engine at idle for at least 2 minutes.




6) Confirm that EGR valve is not lifting. (If necessary, try lifting with a suitable tool.) If NG, go to TROUBLE DIAGNOSES FOR DTC P0400.
7) Check voltage between ECM terminal (63) and ground at about 1,500 rpm with EGR valve lifted up to the full position using a suitable tool. (When lifting up, place the tool as near to valve center as possible. Also, take care not to damage diaphragm.).
Voltage should decrease to less than 1.0V.
8) If step 7 is OK, perform TROUBLE DIAGNOSES FOR DTC P0400 and P1400.




WIRING DIAGRAM




DIAGNOSTIC PROCEDURE

COMPONENT INSPECTION
EGR temperature sensor










Check resistance as shown in the figure.
If NG, replace EGR temperature sensor.