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Home >> Ford >> 1996 >> Aerostar Van Window >> Repair and Diagnosis >> External Pages >> Different car >> Section 43 (Engine Controls - Tests W/Codes - 2.0L A/T) >> Tests >> Test Dd - EGR Valve Position Sensor CKT, EGR Vacuum Solenoid Valve CKT & EGR Vent Solenoid Valve CKT >> Diagnostic Aids

Diagnostic Aids

WARNING: This page is about a different car, the 1995 Mazda MX-6 and 1995 Mazda 626. However, it is still accessible from the selected car via links, so may be relevant.

Perform this test only when directed by QUICK TEST. This circuit test is intended to diagnose:

1) Code 327: Attempt To Generate Code 337  Code 327 indicates EGR valve position sensor signal is less than self-test minimum. Possible causes for this fault are:

Turn ignition off. Disconnect EGR valve position sensor. Connect jumper wire between terminals VREF and EGR valve position sensor signal at EGR valve position sensor wiring harness connector. Repeat KOEO and KOER SELF-TEST. If Code 337 is displayed, replace EGR valve position sensor/EGR valve assembly. Remove jumper wire and repeat QUICK TEST. Disregard any other codes that are set at this time. If Code 337 is not displayed, remove jumper wire and go to next step.

2) Check EGR Valve Position Sensor VREF Voltage  Turn ignition on. Disconnect EGR valve position sensor. Measure voltage between VREF and SIG RTN terminals at EGR valve position sensor connector. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, go to TEST C.

3) Check EGR Circuit Continuity  Turn ignition off. Disconnect PCM 60-pin connector and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (49-UN01-058), leaving PCM disconnected. Measure resistance between EGR terminal at EGR valve position sensor connector and test pin No. 46 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open circuit. Remove breakout box, reconnect all components and repeat QUICK TEST.

4) Check For Short To Ground In EGR Circuit  Turn ignition off. With breakout box installed and PCM disconnected, measure resistance between test pin No. 27 and test pins No. 40, 46 and 60 at breakout box. If all readings are more than 10,000 ohms, replace PCM. Remove breakout box, reconnect all components and repeat QUICK TEST. If any reading is 10,000 ohms or less, repair short to ground. Remove breakout box, reconnect all components and repeat QUICK TEST.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 4) to step 10). No test procedures have been omitted.

10) Code 337: Attempt To Generate Code 327  Code 337 indicates EGR valve position sensor signal is more than self-test minimum. Possible causes for this fault are:

Turn ignition off. Disconnect EGR valve position sensor. Connect jumper wire between EGR valve position sensor signal and SIG RTN terminals at EGR valve position sensor wiring harness connector. Repeat KOEO and KOER SELF-TEST. If Code 327 is displayed, remove jumper wire and go to step 13). Disregard any other codes that are set at this time. If Code 327 is not displayed, remove jumper wire and go to next step.

11) Check EGR Valve Position Sensor VREF Voltage  Turn ignition on. Disconnect EGR valve position sensor. Measure voltage between VREF and SIG RTN terminals at EGR valve position sensor connector. If voltage is 4-6 volts, replace EGR vlave position sensor/EGR valve assembly. Repeat QUICK TEST. If voltage is not 4-6 volts, go to TEST C.

12) Check For Short To Power In EGR Circuit  Turn ignition off. Disconnect PCM 60-pin connector and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Disconnect EGR valve position sensor. Install Breakout Box (49-UN01-058), leaving PCM disconnected. Measure resistance between test pin No. 27 and test pins No. 26, 37 and 57 at breakout box. If all readings are more than 10,000 ohms, replace PCM. Remove breakout box, reconnect all components and repeat QUICK TEST. If any reading is less than 10,000 ohms, repair short circuit. Remove breakout box, reconnect all components and repeat QUICK TEST.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 12) to step 20). No test procedures have been omitted.

20) KOEO Code 571 & 572: Check EGR Vent & Vacuum Solenoid Valves Resistance  Code 571 indicates failure in EGR vent solenoid valve circuit. Code 572 indicates failure in EGR vacuum solenoid valve circuit. Possible causes for this fault are:

Turn ignition off. Disconnect EGR Vent (Code 571) or EGR Vacuum (Code 572) solenoid valve. Measure resistance between solenoid valve connector terminals. If resistance is 30-70 ohms, go to next step. If resistance is not 30-70 ohms, replace solenoid valve and repeat QUICK TEST.

21) Check Solenoid Valve VPWR Circuit  Turn ignition on. Disconnect solenoid valve to be tested. Measure voltage between negative battery terminal and VPWR terminal at solenoid valve connector. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open circuit. Repeat QUICK TEST.

22) Check Solenoid Valve Circuit Continuity  Turn ignition off. Disconnect solenoid valve to be tested. Disconnect PCM 60-pin connector, inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (49-UN01-058), leaving PCM disconnected. If testing EGR vent solenoid valve, measure resistance between test pin No. 12 at breakout box and EGR vent solenoid valve terminal at solenoid valve connector. If testing EGR vacuum solenoid valve, measure resistance between test pin No. 33 at breakout box and EGR vacuum solenoid valve terminal at solenoid valve connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open circuit. Remove breakout box, reconnect all components and repeat QUICK TEST.

23) Check For Solenoid Valve Circuit Short  If testing EGR vent solenoid valve, measure resistance between test pin No. 12 and test pins No. 40, 46 and 60 at breakout box. If testing EGR vacuum solenoid valve, measure resistance between test pin No. 33 and test pins No. 40, 46 and 60 at breakout box. If all readings are more than 10,000 ohms, replace PCM. Remove breakout box, reconnect all components and repeat QUICK TEST. If any reading is 10,000 ohms or less, repair short circuit. Remove breakout box, reconnect all components and repeat QUICK TEST.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 23) to step 30). No test procedures have been omitted.

30) KOER Code 332: Check Vacuum To EGR Valve  Code 332 indicates EGR valve position sensor input did not change after PCM commanded EGR valve to open. Possible causes for this fault are:

Turn ignition off. Disconnect EGR vacuum hose at EGR valve and connect vacuum gauge to disconnected vacuum hose. Repeat KOEO SELF-TEST, while observing vacuum gauge. If vacuum is less than 1.0 in. Hg throughout KOEO SELF-TEST, go to next step. If vacuum is 1.0 in. Hg or more throughout KOEO SELF-TEST, replace EGR valve position sensor/EGR valve. Reconnect all components and repeat QUICK TEST.

31) Check EGR Vacuum Hose  Disconnect EGR valve vacuum hose. Insect vacuum hose between EGR valve and both EGR solenoid valves. Replace hose as necessary. Repeat QUICK TEST. If vacuum hose is okay, reconnect vacuum hose and go to next step.

32) Check Vacuum To EGR Vacuum Solenoid Valve  Turn ignition off. Disconnect vacuum hose from EGR vacuum solenoid valve input port. Install vacuum gauge to disconnected hose. Start engine and allow it to idle. If vacuum is more than 10 in. Hg, remove vacuum gauge. Reconnect vacuum hose and go to next step. If vacuum is 10 in. Hg or less, check vacuum hose to EGR vacuum solenoid valve. Replace hose as necessary. If vacuum hose is okay, check vacuum source for solenoid valve. Repair as necessary. Repeat QUICK TEST.

33) Check EGR Vacuum Solenoid Valve  Turn ignition off. Disconnect vacuum hose from EGR vacuum solenoid valve output port. Install vacuum gauge to output port of EGR vacuum solenoid valve. Repeat KOEO SELF-TEST and observe vacuum gauge. If vacuum signal decreases then increases, remove vacuum gauge and go to next step. If vacuum signal does not decrease then increase, replace EGR vacuum solenoid valve. Remove vacuum gauge. Reconnect all components and repeat QUICK TEST.

34) Check EGR Vacuum Solenoid Valve Output Port Vacuum Hose  Disconnect vacuum hose from EGR vacuum solenoid valve output port. Inspect vacuum hose for obstructions, cracks and kinks. Replace vacuum hose as necessary and repeat QUICK TEST. If vacuum hose is okay, reconnect vacuum hose and go to next step.

35) Check EGR Vent Solenoid Valve Vacuum Hose  Disconnect EGR vent solenoid valve vacuum hose. Inspect vacuum hose for obstructions, cracks and kinks. Replace vacuum hose as necessary and repeat QUICK TEST. If vacuum hose is okay, replace EGR vent solenoid valve. Reconnect vacuum hose and repeat QUICK TEST.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 35) to step 90). No test procedures have been omitted.

90) Continuous Memory Code 327 Or 337: Check For Intermittent Sensor  Continuous Memory Code 327 indicates EGR valve position sensor input to PCM was below minimum acceptable voltage sometime during vehicle operation. Continuous Memory Code 337 indicates EGR valve position sensor input to PCM was more than the maximum acceptable voltage sometime during vehicle operation. Possible causes for this fault are:

Enter CONTINUOUS MONITOR MODE (WIGGLE TEST). Observe test equipment and perform the following:

If a fault is indicated, inspect EGR valve position sensor connector and terminals. Repair as necessary. If connector and terminals are okay, replace EGR valve position sensor/EGR valve assembly. Clear codes and repeat QUICK TEST. If a fault is not indicated, go to next step.

91) Check For Intermittent Harness Damage  While still in CONTINUOUS MONITOR MODE (WIGGLE TEST), observe test equipment and perform the following. Shake and bend small sections of wiring harness starting at EGR valve position sensor and working toward dash panel. Also, shake and bend small sections of wiring harness starting at dash panel and working toward PCM. If a fault is indicated, isolate fault and repair as necessary. Clear codes and repeat QUICK TEST. If a fault is not indicated, go to next step.

92) Check PCM Connector  Turn ignition off. Disconnect PCM 60-pin connector and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Clear codes and repeat QUICK TEST. If connector and wiring are okay, fault cannot be duplicated at this time. Testing is complete.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 92) to step 100). No test procedures have been omitted.

100) Continuous Memory Code 332: Check EGR Valve Function  Continuous Memory Code 332 indicates EGR valve did not open when engine load and requested conditions had been met sometime during vehicle operation. Possible causes for this fault are:

Turn ignition off. Disconnect and plug EGR valve vacuum line at EGR valve. Connect vacuum pump to EGR valve. Apply 10 in. Hg to EGR valve. Observe EGR valve and release vacuum. If EGR valve functions properly, remove vacuum pump. Unplug vacuum hose and go to next step. If EGR valve does not function properly, remove EGR valve position sensor/EGR valve assembly. Inspect EGR valve for blockage, binding, contamination and leakage. Repair or replace EGR valve assembly as necessary. Clear codes and repeat QUICK TEST.

101) Check EGR Valve Vacuum Hose  Disconnect EGR vacuum hose at vacuum source and EGR valve. Inspect vacuum hose for obstructions, cracks and kinks. Replace vacuum hose as necessary. Clear codes and repeat QUICK TEST. If vacuum hose is okay, reconnect vacuum hose and go to next step.

102) Check EGR Vacuum & Vent Solenoid Valve Vacuum Hoses  Disconnect solenoid valve vacuum hose to be checked. Inspect vacuum hose for obstructions, cracks and kinks. Replace vacuum hose as necessary. Clear codes and repeat QUICK TEST. If vacuum hose is okay, reconnect vacuum hoses and go to next step.

103) Check EGR Vacuum & Vent Solenoid Valves & Circuits For Intermittent Fault  Turn ignition off. Disconnect vacuum hose at EGR valve and connect vacuum pump to disconnected hose. Start engine and allow it to idle. Observe vacuum pump for increased vacuum while performing the following:

If vacuum reading increased, isolate fault and repair as necessary. Clear codes and repeat QUICK TEST. If vacuum reading did not increase, fault cannot be duplicated at this time. Testing is complete.

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