Diagnostic Procedure

EGR Temperature Sensor P1401










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.


DIAGNOSTIC TROUBLE CODE DETECTING CONDITION

PROCEDURE FOR MALFUNCTION A

WITH CONSULT
(1) Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT.






(2) Confirm that engine coolant temperature is lower than 50°C (122°F). (If necessary, wait until the temperature equals atmospheric temperature.)
(3) Start engine and run it for at least 8 seconds at idle speed.

OR

WITH GST
(1) Turn ignition switch "ON" and select "MODE 1" with GST






(2) Confirm that the engine coolant temperature is lower than 50°C (122°F). (If necessary, wait until the coolant temperature is the same as atmospheric temperature.)
(3) Start engine and run it for at least 8 seconds at idle speed.
(4) Select "MODE 3" with GST

OR

WITH NO TOOLS
(1) Turn ignition switch "ON"and confirm that voltage between ECM terminal (51) and ground is more than 2.35 V (If necessary, wait until coolant temperature is the same as atmospheric temperature.)







(2) Start engine and run it for at least 8 seconds at idle speed.
(3) Turn ignition switch "OFF" wait for at least 3 seconds and then "ON".
(4) Perform "Diagnostic Test Mode II (Self Diagnostic results)" with ECM.


PROCEDURE FOR MALFUNCTION B

WITH CONSULT
(1) Start engine and warm it up suffciently.
(2) Turn ignition switch "OFF", wait for at least 3 seconds and then start engine again.
(3) Select "DATA MONITOR" mode with Consult
(4)Run engine for at least 5 seconds at idle speed.

OR

WITH GST
(1) Start engine and warm it up suffciently.
(2) Turn ignition switch "OFF", wait for at least 3 seconds and then start engine again.
(3) Run engine for at least 5 seconds at idle speed.
(4) Select "MODE 3" with GST

OR

WITH NO TOOLS
(1) Start engine and warm it up suffciently.
(2) Turn ignition switch "OFF", wait for at least 3 seconds and then start engine again.
(3) Run engine for at least 5 seconds at idle speed.
(4) Turn ignition switch "OFF", wait for at least 3 seconds and then "ON".
(5) Perform "Diagnostic Test Mode II (Self Diagnostic results)" with ECM.

WIRING DIAGRAM






DIAGNOSTIC PROCEDURE






COMPONENT INSPECTION






Check resistance change and resistance value @ 100°C (212°F).

Note: Resistance should decrease in response to teperature increase.

Resistance: 100°C (212°F) 85.3 +/-8.53 K ohms

If NG, replace EGR temperature sensor.