CHECK ENGINE LIT ON

MICHAEL WELCH

MEMBER
1994 MERCURY SABLE
6 CYL
FWD
AUTOMATIC
108,800 MILES

94 MERCURY SABLE SCANNED CAR READS #326 and #327 AND #624 ELECTRIC PRESSURE CONTROL can't fiqure it OUT, CHECKED MANY ITEMS LIKE EGR AND CHANGED SENSOR, CLEANED THE EGR, REPLACED EGR VACUUM SOLENOID, REPLACE FRONT SENSOR 3 WEEKS AGO, CHECKED ALL WIRE CONNECTIONS IN THAT AREA AND THE CAR RUNS FINE WITHOUT PROBLEMS BUT THE LITE COMES AND GOES LIGHT STILL ON out/ please help mike

1 Reply

BMRFIXIT

MECHANIC
19,053 POSTS

10) Continuous Memory Code 326
Code 326 indicates that within previous 40 warm-up cycles, PCM detected EGR flow at idle. Possible causes for this fault are:
EGR valve stuck open.
Faulty EGRT sensor.
Open or shorted wiring harness circuit.
Clear codes from PCM memory. Start engine, and let it run for at least 2 minutes. If engine idles rough or stalls, clean or replace EGR valve. If engine does not stall or idle rough, go to next step.
11) Verify Condition
Repeat KOEO SELF-TEST. If Continuous Memory Code 326 is not present, go to step 90). If Continuous Memory Code 326 is present, go to next step.
12) Check Continuity Of Harness Circuits
Turn ignition off. Disconnect PCM 60-pin connector. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Disconnect EGRT sensor connector. Measure resistance between EGRT terminal at EGRT wiring harness connector and test pin No. 43 at breakout box. Also, measure resistance between SIG RTN terminal at EGRT wiring harness connector and test pin No. 46 at breakout box. If either resistance is 5 ohms or more, repair open circuit. Remove breakout box, reconnect all components, and repeat QUICK TEST. If either resistance is less than 5 ohms, replace EGRT sensor. Remove breakout box, reconnect all components, and repeat QUICK TEST

1) Continuous Memory Code 327: Verification
Code 327 indicates that at least once within previous 40 warm-up cycles, EGRT sensor signal was less than self-test minimum. Possible causes for this fault are:
Faulty EGRT sensor.
Open or grounded wiring harness.
Faulty PCM.

Clear codes from PCM memory. Disconnect EGRT sensor. Start engine, and let it run for at least 2 minutes. Repeat KOEO SELF-TEST. If Code 337 is not displayed, go to next step. If Code 337 is displayed, replace EGRT sensor. Clear continuous memory, and repeat QUICK TEST.
3) Check EGRT Circuit For Short To Ground
Turn ignition off. Disconnect PCM 60-pin connector. Inspect connector for damaged pins, corrosion and loose wires. Repair as necessary. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Disconnect EGRT sensor wiring harness connector. Measure resistance between test pin No. 43 and pins No. 40, 46 and 60 at breakout box. If all readings are 10,000 ohms or more, 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.