DRIVEABILITY Test No 10 - EGR System (Code 32)
- With tester connected to diagnostic connector. Connect analog voltmeter positive lead to Gray/Yellow wire of 4-pin EGR/purge solenoid connector. Connect voltmeter negative lead to ground. Put system in ATM Test "11". Refer to ENTERING ON-BOARD DIAGNOSTICS in this article. If voltmeter reads battery voltage and is not pulsating and solenoid does not click, go to next step. If voltmeter reads zero volts and solenoid does not click, go to step 3). If voltmeter reading pulsates between one volt and battery voltage and solenoid does not click, replace EGR solenoid. If voltmeter reading pulsates between one volt and battery voltage and solenoid clicks, go to step 5).
- Turn ignition off. Disconnect 60-pin connector from SMEC. Connect voltmeter between Gray/Yellow wire in cavity No. 40 and ground. Turn ignition switch to "RUN" position. If voltmeter reads battery voltage, replace SMEC. Before replacing SMEC, ensure cavity No. 40 in 60-pin connector is not damaged causing a poor connection. If voltmeter reads zero volts, repair Gray/Yellow wire of cavity No. 40 for an open circuit to solenoid connector.
- Turn ignition off. Connect a voltmeter between Dk. Blue wire of EGR/purge solenoid 4-pin connector and ground. Turn ignition on. If voltmeter reads zero volts, repair Dk. Blue wire for an open circuit to wiring harness splice. If voltmeter reads battery voltage, go to next step.
- Turn ignition off. Disconnect 60-pin connector from SMEC. Connect a voltmeter between Gray/Yellow wire at cavity No. 40 and ground. Turn ignition on. If voltmeter reads battery voltage, replace SMEC for a bad logic board. If voltmeter reads zero volts, replace EGR solenoid.
- Disconnect vacuum line at EGR backpressure valve that comes from throttle body or solenoid. Connect a vacuum gauge to line from throttle body or solenoid. Start engine. Disconnect AIS motor. When engine reaches normal operating temperature, raise engine speed to 2500 RPM. If vacuum gauge reads at least 5 in. Hg vacuum, note reading and go to next step. If vacuum gauge reads less than 5 in. Hg vacuum or zero, repair vacuum supply from throttle body or solenoid. If vacuum lines are okay, replace EGR solenoid.
- With engine running, disconnect vacuum gauge and connect vacuum hose to backpressure valve. Disconnect vacuum line from EGR valve and connect a vacuum gauge to line. Disconnect AIS motor. Raise engine speed to 2500 RPM. If vacuum gauge reads the same or near the same as in step 5), go to next step. If vacuum gauge is not reading the same or near the same as in step 5), replace EGR/backpressure valve assembly.
- Connect a vacuum pump to EGR valve. With AIS motor disconnected and engine idling, slowly apply vacuum. If engine speed begins to drop when vacuum reaches 2.5-3.5 in. Hg vacuum, go to next step. If engine speed does not drop, replace EGR/backpressure valve assembly.
- Reconnect AIS motor. Apply 10 in. Hg vacuum to EGR valve. If vacuum holds without bleeding for at least 10 seconds, go to DRIVEABILITY TEST NO 18 . If vacuum bleeds down before 10 seconds, replace EGR/backpressure assembly.