MAF Sensor - MIL ON/DTC's Set/Driveability Concerns

Article No.
97-3-3

02/03/97

^ HESITATION - HESITATION ON ACCELERATION - REDUCED POWER - ROUGH IDLE - DIAGNOSTIC TROUBLE CODE (DTC) 181 OR P0171 MAY BE STORED IN MEMORY - VEHICLES BUILT THROUGH 11/19/95

^ MALFUNCTION INDICATOR LAMP (MIL) - DIAGNOSTIC TROUBLE CODE (DTC) 181 OR P0171 MAY BE STORED IN MEMORY - ROUGH IDLE - REDUCED POWER - HESITATION ON ACCELERATION - VEHICLES BUILT THROUGH 11/19/95

^ REDUCED POWER - HESITATION ON ACCELERATION - ROUGH IDLE - DIAGNOSTIC TROUBLE CODE (DTC) 181 OR P0171 MAY BE STORED IN MEMORY - VEHICLES BUILT THROUGH 11/19/95

^ ROUGH IDLE - REDUCED POWER - HESITATION ON ACCELERATION - DIAGNOSTIC TROUBLE CODE (DTC) 181 OR P0171 MAY BE STORED IN MEMORY - VEHICLES BUILT THROUGH 11/19/95

^ LAMP - MALFUNCTION INDICATOR LAMP (MIL) - DIAGNOSTIC TROUBLE CODE (DTC) 181 OR P0171 MAY BE STORED IN MEMORY - ROUGH IDLE - REDUCED POWER - HESITATION ON ACCELERATION - VEHICLES BUILT THROUGH 11/19/95

FORD:
1993-96 PROBE

ISSUE:
A hesitation on acceleration, reduced power, rough idle and/or a Malfunction Indicator Lamp (MIL) illumination with Diagnostic Trouble Code (DTC) 181 (1993-95 Probe) or P0171 (1996 Probe) may be evident on some vehicles. This may be caused by the Mass Air Flow (MAF) sensor.

ACTION:
Replace the MAF sensor with a revised MAF sensor. The revised MAF sensor should reduce the possibility of these concerns. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

1. Check the vehicle for vacuum leaks and repair as required.

2. Verify the vehicle has the proper Positive Crankcase Ventilation (PCV) valve installed.

3. Run an EEC self test, record any DTCs and repair as required. If the concern is still present, proceed to the next Step.

4. Check the vehicle's fuel pressure. Refer to the appropriate year Probe Service Manual, Section 9B for details.

5. Check the MAF sensor voltage in Park or Neutral at 5,500 rpms using New Generation Star (NGS) Tester, Service Bay Diagnostic System (SBDS) or a breakout box. If voltage is less than 2.3 volts, proceed to the next Step.

6. Inspect the MAF sensor build date. If the sensor was built before 5K05 (1st digit = year, 2nd digit = month (A = January, B = February, etc.), 3rd and 4th digits = day of month), replace the sensor with a new sensor.

7. Clear all DTCs and rerun self test to verify repair.

PART NUMBER PART NAME

F32Z-12B579-B Mass Air Flow (MAF) Sensor (1993-95 Probe)
F62Z-12B579-CA Mass Air Flow (MAF) Sensor (1996 Probe)

OTHER APPLICABLE ARTICLES: NONE

WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage And Emission Warranty Coverage

OPERATION DESCRIPTION TIME

970303A Replace Mass Air Flow 0.3 Hr.
(MAF) Sensor

DEALER CODING
CONDITION
BASIC PART NO. CODE
12B579 42

OASIS CODES: 206000, 607000, 607400, 607700, 608000, 608400, 610000, 610600, 611000, 611500, 614000, 614500, 616000, 698298