Crown Victoria V8-4.6L SOHC VIN 6 (1996)
Air Flow Meter/Sensor: Customer Interest
Engine - Detonation/Spark Knock On Acceleration
Article No.
97-21-6
10/13/97
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DETONATION - DURING ACCELERATION -
VEHICLES BUILT THROUGH 8/97
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NOISE - "SPARK KNOCK" DURING
ACCELERATION - VEHICLES BUILT THROUGH 8/97
FORD:
1996-97 CROWN VICTORIA
LINCOLN-MERCURY:
1996-97 GRAND MARQUIS, TOWN CAR
CALIBRATION:
6-18E-R05-R11, 6-18F-R05-R11, 6-18H-R05-R11, 6-18I-R05-R12, 6-18J-R05-R11, 6-18M-R05-R11, 6-18N-R05-R11, 6-18Q-R05-R11,
6-18S-R05-R11, 7-18E-R10, 7-18F-R05-R10, 7-18H-R05-R10, 7-18I-R05-R11, 7-18J-R10, 7-18M-R05-R10, 7-18N-R05-R10, 7-18Q-R10, 7-185-R10
All prior calibration revision levels to the calibrations listed above are also included in this TSB.
WARNING:
THIS MODIFICATION IS AUTHORIZED ONLY FOR THE LISTED ENGINE. PERFORMING THIS MODIFICATION ON OTHER ENGINE
CALIBRATIONS IS UNAUTHORIZED AND COULD CREATE LIABILITY UNDER APPLICABLE FEDERAL OR LOCAL LAWS.
ISSUE:
Some vehicles may experience detonation during acceleration. This may be caused by contamination of the Mass Air Flow (MAF) sensor which then
misinterprets the barometric pressure resulting in a leaner than desired condition.
ACTION:
Replace the MAF sensor and reprogram the Powertrain Control Module (PCM). The sensor has been revised to reduce the possibility of contamination
and reduce the possibility of spark knock. Refer to the following text and PCM Application Chart for details.
If detonation occurs during moderate to wide open throttle, verify the barometric pressure sensor output is above 148 Hz. This can be accomplished by
using the New Generation Star (NGS) Tester and by calling up the Parameter Identification Display (PID) called "BARO" or "BP" depending on which
level of NGS software is used.
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If the "BP" is 148 Hz or less, disconnect the MAF sensor hardshell connector. Cycle the ignition key twice and drive the vehicle until the
Malfunction Indicator Lamp (MIL) is illuminated. Verify that the 'BP" has gone to 157 Hz (default FMEM value) and try to duplicate detonation
concern.
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If the detonation is eliminated, replace the MAF sensor.
NOTE:
REGIONAL APPROVAL MUST BE OBTAINED WHEN IT IS NECESSARY TO REPLACE THE PCM. EMERGENCY ORDERS ONLY WILL
BE FILLED AS SHELF STOCK OF PCMs ARE LIMITED.
