Mazda MX-6 1998, Workshop Manual

Page: 299 / 1282

TROUBLESHOOTING [ENGINE CONTROL KL]
DTC P1100
MAF sensor intermittent
DESCRIPTION
• Continuous Memory DTC P1100 indicates MAF sensor signal went below 0.39 volts or
above 4.35 volts (refer to Voltage to Mass Air Flow Conversion Table at beginning of this
Test In 01-40B MASS AIR FLOW SENSOR INSPECTION [KL]) sometime during last 40
warm-up cycles
[Possible Cause]
• Poor continuity with MAF sensor connector • MAF harness intermittent short
• Poor continuity with MAF harness • MAF sensor internal intermittent open or short
STEP INSPECTION ACTION
1 CHECK FOR MAF SIGNAL CIRCUIT
INTERMITTENT VOLTAGE INPUT
• Start engine and bring to idle.
Note
• If stabilized idle is not stabilized at
minimum of 700 rpm, go to ENGINE
SYMPTOM TROUBLESHOOTING.
• NGS tester connected.
• Run throttle up to 1,500 rpm for 5 seconds,
then bring back to idle.
• Access MAF PID for fault indication while
performing following:
• Lightly tap on MAF sensor and wiggle
harness connector to simulate road
shock
• Is MAF PID within specified value?
tr
01-40B MASS AIR FLOW SENSOR
INSPECTION [KL]
Yes
DISCONNECT and INSPECT MAF sensor connector.
If okay, REPLACE MAF sensor.
RESET PCM to completely clear DTCs.
t
r
After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No Go to next step.
2 CHECK MAF HARNESS TO PCM FOR
INTERMITTENT OPENS OR SHORTS
• Key off.
• Disconnect PCM. Inspect for damaged or
pushed out pins, corrosion, loose wires,
etc. Service as necessary.
• Install breakout box. Reconnect PCM.
• Key on, engine off.
• Connect DVOM between Test Pin 88 and
Test Pin 36 at breakout box.
• W hile viewing DVOM, do following:
• Grasp vehicle harness closest to MAF
sensor connector
• Shake and bend small section of
harness all way to dash panel
• Wiggle, shake and bend harness from
dash panel to PCM
• Does voltage go below minimum 0.39
volts or above maximum 3.90 volts?
Yes ISOLATE fault and SERVICE as necessary.
RECONNECT all components.
RESET PCM to completely clear DTCs.
ny
After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No Unable to duplicate and/or identify fault at this time.
Intermittent poor connection or component malfunction
(REPAIR or REPLACE as necessary).
Go to SYMPTOM TROUBLESHOOTING No.27.
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