EGR Control Solenoid: Testing and Inspection

Wiring Diagram:

A faulty EGR control solenoid will set code 34 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

Diagnostic Chart:

EGR CONTROL SOLENOID DIAGNOSTIC CHART


1. CHECK ECM VOLTAGE
a. With ignition "ON," measure voltage between ECM and ground.
Connector (terminal) Voltage
B62(14) & ground min 10 VDC

Should read 10-13V.

2. CHECK HARNESS CONNECTOR BETWEEN ECM AND MAIN RELAY
a. Turn ignition "OFF".
b. Disconnect ECM and main relay connectors.
c. Measure resistance between ECM connector and relay connector.
Connector (terminal) Resistance
B62(14) & B52(4) 0 ohms

3. CHECK POWER SUPPLY TO MAIN RELAY
a. Turn ignition "ON".
b. Disconnect main relay connector.
c. Measure voltage between relay connector and ground.
Connector (terminal) Voltage
B52(1) & ground min 10 VDC
B52(2) & ground min 10 VDC

4. CHECK INPUT SIGNAL FROM EGR CONTROL SOLENOID
a. Turn ignition "ON".
b. Disconnect main ECM connector.
c. Measure voltage between ECM connector and ground.
Connector (terminal) Voltage
B62(22) & ground min 7 VDC

Harness:

5. CHECK HARNESS CONTINUITY BETWEEN ECM AND EGR SOLENOID
a. Turn ignition "OFF".
b. Disconnect ECM and solenoid connectors.
c. Measure resistance between ECM connector and solenoid connector.
Connector (terminal) Resistance
B62(22) & E16(2) 0 ohms


6. CHECK EGR SOLENOID
a. Check resistance between "+" and "-" terminals. If not between 32.7 and 39.9 ohms, replace valve.
b. Check resistance between "+" or "-" terminal and ground. If not 1M ohms or more, replace valve.
c. Check that the vacuum passage opens and closes while applying current. If not, replace valve.

EGR Solenoid:

When current is "OFF," spring pressure closes the passage between "A" and "B" and opens the passage between "B" and "C." When current is "ON," the passage between "A" and "B" is opened and the passage between "B" and "C" is closed.