Exhaust Gas Recirculation: Testing and Inspection
EXC. 1986-87 FEDERAL CRX HF
Vacuum Is Available For Condition 1
1. Check for proper vacuum hose routing. If routing is satisfactory, replace EGR control valves A and B.
No Vacuum Available For Condition 2 & 3, 1500 Auto. Trans. & CRX HF Man. Trans.; No Vacuum Available Condition 3 1500 Man. Trans. Exc. CRX HF
1. Check for voltage at EGR control solenoid valve A.
2. If voltage is present, proceed as follows:
a. Check control switch and thermosensor B for proper operation.
b. Check voltage at black/yellow wire of control unit connector with ignition switch in the ``On'' position. If voltage is not present, check fuse and wiring.
c. Check black wire for continuity between control unit and ground. Continuity should be present.
3. If no voltage is present, proceed as follows:
a. Disconnect number 15 vacuum hose from EGR control solenoid valve A. Check for vacuum at hose with engine at 4500 RPM.
b. If vacuum is not present, check vacuum line routing and carburetor port. If vacuum is present, replace EGR control solenoid valve A.
Vacuum Available For Condition 2, Civic 1500 W/Man. Trans. Exc. CRX HF
1. If voltage is present at gray terminal, replace EGR control solenoid valve A.
2. If voltage is not present at gray terminal, proceed as follows:
a. Check voltage at blue wire of control unit connector with ignition switch in the ``On'' position. If voltage is not present, check blue wire between ignition coil and control unit. Repair or replace as required.
b. Check vacuum switch B for proper operation.
c. Check voltage at black/yellow wire of control unit connector with ignition switch in the ``On'' position. If voltage is not present, check wiring. Repair or replace as required.
d. Check brown/black wire for continuity between control unit and ground. Continuity should be present.
No Voltage For Condition 2 But Vacuum Is Greater Than 3 In. Hg, Civic 1300 & CRX 1500 HF
1. Replace EGR control solenoid valve B.
Fig. 67 Device control unit self-diagnosis chart.:
Fig. 68 Device control unit input troubleshooting.:
1986-87 CRX HF EXC. CALIFORNIA
The device control unit on these models is equipped with a self-diagnosis function. When an abnormality is sensed in one of the controlled circuits, the LED display on the control unit will light, and the malfunction can be determined by the pattern of the illuminated LEDs.
There are 4 LEDs on the control unit (located under passenger seat), and they are numbered 1, 2, 4 and 8 as viewed from right to left. If a malfunction is sensed and stored in the control unit memory, the appropriate LEDs will be lit whenever the ignition switch is on.
If there is voltage from the control unit when no voltage should be available, or if no voltage is available when there should be voltage and the device circuit is satisfactory, check the LED display on the control unit. If the LEDs are lit, note the pattern and refer to the diagnosis chart, Fig. 67, to locate the malfunction. If voltages are incorrect but the LEDs are not lit, refer to diagnosis chart, Fig. 68, and check the appropriate input signal circuits.
After making repairs and ensuring that the affected system operates properly, disconnect battery ground cable for at least 10 seconds to reset self-diagnosis system. After reconnecting the battery cable, ensure that all LEDs are off. To test the LED display and self-diagnosis system, turn ignition on while observing LEDs. If system is functioning normally, all LEDs should light for approximately 2 seconds.