Test Z - EGR Control Test
- Turn ignition off and wait 10 seconds. Disconnect harness at EGR solenoid. With DVOM on 200 ohm scale, measure solenoid resistance. If reading is 65-110 ohms, reconnect EGR solenoid and go to next step. If reading is less than 65 ohms or greater than 110 ohms, replace EGR solenoid and repeat Quick Test.
- Turn ignition off and wait 10 seconds. Enter Output State Check and perform Key On-Engine Off Self-Test until end of Continuous code display. DVOM will indicate zero volts. Depress and release throttle and observe DVOM. If reading goes high, remain in Output State Check and go to next step. If reading does not go high, depress throttle to wide open position and release. If reading still does not go high, go to TEST O - NO CODES, IMPROPER CODES , step 13). Leave equipment connected.
- With DVOM on 20 volt scale, connect positive lead to vehicle power circuit and negative lead to EGR output circuit at EGR solenoid harness. While observing DVOM, depress and release throttle several times to cycle output on and off. If EGR output cycles on and off, go to next step. If EGR output does not cycle on and off, go to step 6).
- Disconnect vacuum line at EGR solenoid supply port and install vacuum pump. Disconnect vacuum line at EGR solenoid output port and install vacuum gauge. While maintaining 6 in. Hg vacuum on EGR solenoid, depress and release throttle to cycle output on and off and observe vacuum gauge. If vacuum output cycles on and off, go to next step. If vacuum output does not cycle on and off, replace EGR solenoid and repeat Quick Test.
- Disconnect vacuum lines at EGR solenoid and start engine. If vacuum is present, EEC system okay, service EGR control system. If vacuum is not present, repair source of vacuum leak or blockage and repeat Quick Test.
- Turn ignition on (engine off). With DVOM on 20 volt scale, connect positive lead to vehicle power circuit at EGR solenoid harness and negative lead to good ground. If reading less than 10.5 volts, repair open circuit and repeat Quick Test. If reading 10.5 volts or more, go to next step.
- Turn ignition off and wait 10 seconds. Disconnect 60-pin connector at ECA and inspect. Repair as required. Connect breakout box and leave ECA disconnected. With DVOM on 200 ohm scale, measure continuity from box pin 35 to EGR circuit at EGR solenoid harness. If reading 5 ohms or more, repair open circuit and repeat Quick Test. If reading less than 5 ohms, go to next step.
- Turn ignition off and wait 10 seconds. Breakout box installed and ECA and EGR solenoid disconnected. With DVOM on 200,000 ohm scale, measure resistance from box pin 35 to pins 37 and 57. If reading 10,000 ohms or more, go to next step. If reading less than 10,000 ohms, repair short to power and repeat Quick Test.
- Turn ignition off and wait 10 seconds. Breakout box installed and ECA and EGR solenoid disconnected. With DVOM on 200,000 ohm scale, measure resistance from box pin 35 to pins 40, 46 and 60 in turn. If reading 10,000 ohms or more, replace ECA and repeat Quick Test. If reading less than 10,000 ohms, repair short to ground and repeat Quick Test.