need help with 4x4 light. it keepe blinking on and off.i checked there are no codes

 

Misery loves company. I have the same problem with my 2002 Explorer 4.6. The 4X4 high light blinks 7 times. I bought a OBD scanner and that was no help. I cant seem to find anyone who knows this problem. Have you come up with anything yet?

 

no sorry cand find ny help

 

That scanner will only find codes set by the OBD II system. The number of times your 4x4 indicator flashes is the trouble code. All you need is a list of the codes. Courtesy of my Ford factory manual, here is the list.
For example, your light flashes 7 times, so this applies to you:

7 Clutch and rear sensor connectors and/or clutch coil and/or internal circuitry of sensor have discontinuity. First see Step FF1, then Step EE1

I'll post info on the tests (e.g., Test AA) separately.

Good luck!
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Diagnostic Flash Code Information

NOTE: The following flash codes 1 through 16 are On-Board Diagnostic (OBD) codes generated by the control module. If a system fault is detected, the control module will "flash out" the corresponding fault code on the electronic four-wheel drive Malfunction Indicator Lamp (MIL) on the instrument panel. Also, notice that all the codes that can be generated pertain only to the speed sensors, the clutch coil and clutch with the exception of the first flash code.



The electronic four-wheel drive system also includes the brake switch input, Park/Neutral Position (PNP) switch input, one power and two ground lines, along with the E-4WD MIL. The following pinpoint tests include testing on every electronic four-wheel drive circuit and not just those covered by the flash codes.

DIAGNOSTIC FLASH CODE CHART Flash Code Description Action to Take
—Inoperative or Erratic System Errors. Complete Tests AA through DD.
1 Microprocessor RAM (Random Access Memory) access error. Replace Control Module.
2 Clutch connector or clutch coil has discontinuity. GO to Step FF1.
3 Front output speed sensor connector or internal circuitry of sensor has discontinuity. Go to Step EE1.
4 Rear output speed sensor connector or internal circuitry of sensor has discontinuity. Go to Step EE1.
5 Both front and rear speed sensor connectors and/or internal circuitry of sensors have discontinuity. Go to Step EE1.
6 Clutch and front sensor connectors and/or clutch coil and/or internal circuitry of sensor have discontinuity. First see Step FF1, then Step EE1.
7 Clutch and rear sensor connectors and/or clutch coil and/or internal circuitry of sensor have discontinuity. First see Step FF1, then Step EE1.
8 Clutch and both sensor connectors and/or clutch coil and/or internal circuitry of sensors have discontinuity. First see Step FF1, then Step EE1.
9 Mechanical problem that allows clutch plates to slip during clutch engagement (or faulty sensor output signal). First see Step FF1, then Step EE1.
10 Both Code 9 and Code 2. See action for Code 9.
11 Both Code 9 and Code 3. See action for Code 9.
12 Both Code 9 and Code 4. See action for Code 9.
13 Both Code 9 and Code 5. See action for Code 9.
14 Both Code 9 and Code 6. See action for Code 9.
15 Both Code 9 and Code 7. See action for Code 9.
16 Both Code 9 and Code 8. See action for Code 9.



Regeneration (Recovery) of Flash Codes

If the ignition is turned OFF and the code is lost, the ignition will have to be turned ON again to regenerate codes 1 through 8, if the condition or conditions still exist. To regenerate codes 9 through 16, the vehicle must be driven again.

 

Pinpoint Tests

PINPOINT TEST AA: POWER AND GROUNDS

AA1 CHECK FOR OPEN OR INTERMITTENT IN CONTROL MODULE HARNESS CONNECTOR (MHC) PIN 8 (BATTERY +)
Disconnect the module harness connector from the module.
Set the voltmeter on the 20 VDC scale.
Turn the ignition switch to the ON position.
Check voltage between MHC pin 8 and chassis ground. (If there is no voltage, shake the module harness. Re-check for intermittent voltage.)




Is voltage steady (not intermittent) and greater than 9V?
Yes No
GO to AA2 . REPAIR break in the B+ line. REFER to EVTM 's on Aerostar with Electronic Four-Wheel Drive or the Wiring Diagrams.

AA2 CHECK FOR AN INTERMITTENT OR POOR CONTROL MODULE GROUND
Disconnect the battery.
Set the ohmmeter on the 20 ohm scale.
Shake the module harness and check the resistance between MHC pin 12 and chassis ground. Repeat for pin 7 to chassis ground.




Is resistance steady (not fluctuating) and less than 1 ohm?
Yes No
REPLACE control module. REPAIR poor ground circuit(s). REFER to the EVTM 's with Electronic Four-Wheel Drive or the Wiring Diagrams.

PINPOINT TEST BB: ELECTRONIC 4WD MALFUNCTION INDICATOR LAMP

BB1 CHECK FOR VOLTAGE AT CONTROL MODULE HARNESS CONNECTOR PIN 4
Turn the ignition switch to the OFF position.
Back-probe the module harness connector at pin 4 with module connected .
Set voltmeter to the 20 VDC scale.
Check the voltage between pin 4 of the control module and chassis ground with the ignition switch OFF.




Is voltage less than 3V?
Yes No
GO to BB2 . REPAIR short to B+ between control module (pin 4) and the Electronic 4-Wheel Drive Malfunction Indicator Lamp.

BB2 CHECK FOR VOLTAGE AT CONTROL MODULE PIN 4
Back-probe the module harness connector pin 4 with the controller module connected .
Set the voltmeter to the 20 VDC scale.
Turn the ignition switch ON.
Check the voltage between the MHC pin 4 and chassis ground.




Is voltage steady and greater than 9V?
Yes No
GO to BB3 . REPLACE control module.

BB3 CHECK FOR SHORT OR OPEN BETWEEN CONTROL MODULE HARNESS CONNECTOR PIN 4 AND ELECTRONIC 4-WHEEL DRIVE MALFUNCTION INDICATOR CIRCUIT
Turn the ignition switch OFF.
Disconnect the module harness connector from the module.
Set the ohmmeter to the 20 ohm scale.
Check the resistance between the module harness connector pin 4 and chassis ground.




Is resistance greater than 15 ohms?
Yes No
REPLACE the Electronic 4-Wheel Drive Malfunction Indicator Lamp or REPAIR open circuit. REPAIR short to ground between module harness connector pin 4 and the Electronic 4-Wheel Drive Malfunction Indicator Lamp.

PINPOINT TEST CC: BRAKE SWITCH INPUT

CC1 CHECK FOR STOPLAMP OPERATION
Apply the service brakes and observe the rear brakelamps.
Do rear stoplamps illuminate with brake pedal depressed?
Yes No
GO to CC2 . REPAIR the stoplamp circuit and RE-TEST.

CC2 CHECK FOR INTERMITTENT OPEN IN CONTROL MODULE BRAKE SWITCH CIRCUIT
Disconnect the module harness connector from the module.
Set the voltmeter on the 20 VDC scale.
Check the voltage between the module harness connector pin 6 and chassis ground while the brake pedal is depressed.
Shake module harness. Recheck for intermittent voltage.




Is voltage steady (not intermittent) and greater than 9V?
Yes No
REPLACE control module. REPAIR break in the module to brake switch circuit. REFER to EVTM 's on Aerostar with Electronic Four-Wheel Drive or Wiring Diagrams.

PINPOINT TEST DD: PARK/NEUTRAL POSITION SWITCH

DD1 CHECK FOR INTERMITTENT SHORT IN PARK/NEUTRAL POSITION SWITCH (PNP) MODULE HARNESS CONNECTOR PIN 5 (PNP CIRCUIT)
Disconnect the module harness connector from the module.
Set the voltmeter on the 20 VDC scale.
Turn the ignition switch ON.
With the transmission in NEUTRAL, check the voltage between MHC pin 5 and chassis ground.




Is voltage intermittent or steady, and greater than 1V?
Yes No
REPAIR short to voltage in the PNP circuit or REPLACE PNP. GO to DD2 .

DD2 CHECK FOR SHORT TO GROUND IN CONTROL MODULE HARNESS PNP CIRCUIT
Turn the ignition switch OFF.
Disconnect module connector from the module.
Set ohmmeter to the 200 ohm scale.
With the transmission in DRIVE, check the resistance between the module harness connector pin 5 and chassis ground.




Is resistance greater than 100 ohms?
Yes No
GO to DD3 . REPAIR short-to-ground or REPLACE PNP.

DD3 CHECK FOR OPEN BETWEEN CONTROL MODULE HARNESS CONNECTOR AND PNP
Turn the ignition switch to OFF.
Disconnect module harness connector.
Set ohmmeter to the 200 ohm scale.
With the transmission in NEUTRAL, check the resistance between module harness connector pin 5 and chassis ground.




Is resistance less than 50 ohms?
Yes No
REPLACE module. REPAIR open in PNP circuit or REPLACE PNP.

PINPOINT TEST EE: E4WD SPEED SENSORS

EE1 CHECK FOR VOLTAGE AT SPEED SENSOR POSITIVE (+) LINE
Remove the speed sensor connector from each speed sensor.
Set the voltmeter on the 20 VDC scale.
Turn the ignition switch to the ON position.
For each sensor, check the voltage between the sensor harness connector positive (+) pin and chassis ground.
Shake the connector and harness while checking the voltage.




Is voltage steady (not intermittent) and greater than 4V?
Yes No
GO to EE2 . REPAIR open circuit. If fault still occurs REPLACE control module. REFER to the Wiring Diagrams in this section.

EE2 CHECK CONTINUITY OF SPEED SENSOR SIGNAL AND GROUND LINES
Turn the ignition key OFF.
Disconnect the module harness connector from the module.
Remove the speed sensor connector from the speed sensor.
Set the ohmmeter to the 20 ohm scale.
Test the continuity of each wire from the speed sensor connector, from their pins in the sensor harness connector to their corresponding pins in the MHC.




Is resistance greater than 1 ohm?
Yes No
REPAIR open circuit. REFER to the Wiring Diagrams in this section. GO to EE3 .

EE3 CHECK FOR SHORT-TO-GROUND OR INTERMITTENT IN SPEED SENSOR SIGNAL CIRCUIT
Turn the ignition switch OFF.
Disconnect the module harness connector from the module.
Disconnect the speed sensor connector from the speed sensor.
Set the ohmmeter on the 20 ohm scale.
Shake the module harness and sensor harness while checking the resistance between the sensor connector signal pin and chassis ground.




Is resistance below 1 ohm and fluctuating?
Yes No
REPAIR short-to-ground in the speed sensor signal circuit. REFER to the Wiring Diagrams in this section. REPLACE speed sensor. If the fault still occurs REPLACE controller.

PINPOINT TEST FF: E4WD CLUTCH

FF1 CHECK VOLTAGE AT CLUTCH CONNECTOR
Disconnect the clutch harness connector from the clutch line on the transfer case housing.
Set the voltmeter to the 20 VDC scale.
Turn the ignition switch to ON.
Shake the clutch harness and check for battery voltage between the clutch connector pin and chassis ground.




Is voltage present (steady or intermittent)?
Yes No
REPAIR short to B+ on the clutch circuit or REPLACE control module. REFER to the Wiring Diagrams in this section. GO to FF2 .

FF2 CHECK FOR SHORT-TO-GROUND ON CLUTCH CIRCUIT
Turn the ignition switch OFF.
Disconnect the module harness connector from the module.
Set the ohmmeter to the 20 ohm scale.
Shake the module harness connector and check the resistance between MHC pin 14 and chassis ground.




Is resistance intermittent or below 1 ohm?
Yes No
REPAIR short-to-ground on the clutch circuit. REFER to the Wiring Diagrams in this section. GO to FF3 .

FF3 CHECK FOR AN OPEN ON THE CLUTCH CIRCUIT
Turn the ignition switch OFF.
Disconnect the module harness connector from the module.
Set the ohmmeter to the 20 ohm scale.
Shake the module harness connector and check the resistance between MHC pin 14 and pin 13.




Is resistance between 1.5 and 4 ohms?
Yes No
GO to FF4 . REPAIR open in clutch circuit or REPLACE clutch.

FF4 CHECK CLUTCH BY POWERING CIRCUIT
Disconnect the module harness connector from the module.
Connect Clutch Coil Locking Tool D91T-50-CLT or equivalent to the MHC. If tool is not available, ground MHC pin 13 to ground.
Jumper MHC pin 8 to MHC pin 14.
Verify clutch engagement by test driving vehicle in tight turns and noticing driveline wind-up (driveline wind-up is noticed through steering wheel feedback or wheel hop).




Does clutch engage (driveline wind-up)?
Yes No
REPLACE the control module. REPLACE clutch or look for a mechanical failure in the system.

 

Wow, Thanks for the info. I was looking for a factory shop manual myself but have not got my hands on one yet. I will keep looking because this kind of info is just what I need. Time to grab my multimeter and slide under my truck and take a look-see. Thanks again. CCHACE.

 

Oh one more question. Do you know where the control module is located on my 2002 Explorer? I have read different locations from under the glove box to in back of the radio. My current Hayes manual shows me nothing. Thanks CCHACE

 

You're right - it is in different locations for different years. Here's a recent thread that may help:
https://www.ford-trucks.com/forums/5...ghlight=module

The info I posted is for second-gen Explorers (1995-2000, I think), because that's the manual I have. I can't imagine that the testing procedure is any different for later years. Maybe one of the professional techs on the forum can advise?

Cheers,
Kevin