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 Volts DC at 20°C (68°F)
(E31)4-Ground 0.4 - 1.2 Volts DC at 100°C (212°F)

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 maximum

Harness Test:

4. Measure resistance between harness connector at ECM and ground as follows:

Connector & terminal: Resistance:
(E31)4-Ground 1 M.Ohms minimum