EGR Temperature Sensor: Testing and Inspection

A faulty EGR temperature sensor will set code 55 in the on-board diagnostic system.

Wire color code identification:

L: Blue
B: Black
Y: Yellow
G: Green
R: Red
W: White
Br: Brown
Lg: Light green
Gr: Gray


EGR TEMPERATURE SENSOR DIAGNOSTIC CHART

Diagnostic Chart:

CHECK INPUT SIGNAL FOR ECM

Input Signal:

1. Turn ignition switch "ON".
2. Measure voltage between ECM connector and ground as follows:
Connector & terminal: Voltage:
(E31)4-Ground 4 - 4.8 VDC at 68° F (20° C)
(E31)4-Ground 0.4 - 1.2 VDC at 212° F (100° C)


CHECK HARNESS BETWEEN SENSOR AND ECM

Harness Test:

1. Turn ignition switch "OFF".
2. Disconnect EGR temperature sensor harness connector.
3. Measure resistance between harness connector at ECM and sensor as follows:
Connector & terminal: Resistance:
(E31)4-(E15)1 10 ohms max.

Harness Test:

4. Measure resistance between harness connector at ECM and ground as follows:
Connector & terminal: Resistance:
(E31)4-Ground 1 Mohms min.