Mazda MX-6 1998, Workshop Manual

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TROUBLESHOOTING [ENGINE CONTROL KL]
Note
• An intermittent fault can cause continuous memory DTC P0122. If DTC P0122 is still present after
completing step 1 through 4, go to DTC P1125
DTC P0123 TP sensor circuit high input
DESCRIPTION
• DTC P0123 indicates Throttle Position (TP) Sensor signal is greater than self-test
maximum value of 92.27% (4.79 volts)
[Possible Cause]
• TP seated properly (tightened down) • Constant voltage circuit harness short to TP sensor
• Damaged TP sensor power circuit
• TP signal circuit harness short to constant voltage circuit • Open ground harness circuit
or TP sensor power circuit • Damaged PCM
STEP INSPECTION ACTION
1
ATTEMPT TO GENERATE DTC P0122
• Key off.
• Disconnect TP sensor. Inspect for
damaged or pushed out pins, corrosion,
loose wires, etc. Service as necessary.
• Leave TP sensor disconnected.
• Key on, engine off.
• Access TPV PID with NGS tester.
• Is TPV PID less than 0.17 volts?
Yes TP signal circuit is either shorted to constant voltage
circuit in TP sensor or ground circuit is open in TP sensor
or harness.
Go to next step.
No TP signal circuit is shorted to constant voltage circuit or TP
sensor power circuit.
Go to step 3.
2
CHECK CONSTANT VOLTAGE
• Key off.
• TP sensor disconnected.
• Key on, engine off.
• Measure voltage between constant voltage
circuit and ground circuit at TP sensor
vehicle harness connector.
• Is voltage between 4.0 and 6.0 volts?
Yes
TP signal circuit shorted to constant voltage circuit on
ground circuit open in TP sensor.
REPLACE TP sensor.
RERUN OBD Test.
No KEY off. RECONNECT all components.
REPAIR open in constant voltage circuit.
3 CHECK TP SENSOR CIRCUIT FOR
SHORTS TO POWER
• Key off.
• TP sensor disconnected.
• Disconnect PCM. Inspect for damaged or
pushed out pins, corrosion, loose wires,
etc. Service as necessary.
• Install breakout box. Leave PCM
disconnected.
• Measure resistance between Test Pin 89
and Test Pins 90 and 71 or 97 at breakout
box.
• Is each resistance greater than 10,000
ohms?
Yes
TP signal circuit is shorted to constant voltage circuit or TP
sensor power circuit in PCM.
REPLACE PCM.
REMOVE breakout box.
RECONNECT TP sensor.
RESET PCM to completely clear DTCs.
<cr After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No SERVICE Short circuit.
REMOVE breakout box.
RECONNECT all components.
RESET PCM to completely clear DTCs.
ay After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
Note
• An intermittent fault can cause Continuous Memory DTC P0123. If Continuous Memory DTC P0123 is still
present after completing step 1 through step 3, go to DTCs P1120 or P1125.
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