Mazda MX-6 1998, Workshop Manual

Page: 279 / 1282

TROUBLESHOOTING [ENGINE CONTROL KL]
STEP INSPECTION
ACTION
3 INDUCE OPPOSITE FTP SIGNAL
• Key off.
• Disconnect FTP sensor vehicle harness
connector.
• Connect jum per wire between sensor
constant voltage circuit and FTP signal
circuit at FTP sensor vehicle harness
connector.
• Key on, engine off.
• If NGS tester communication concern
exists, remove jumper immediately and go
directly to next step.
• Access FTP V PID with NGS tester.
• Is constant voltage between 4.0 and 6.0
volts?
Yes REPLACE damaged FTP sensor.
tr 0 1-16 EMISSION SYSTEM (FUEL TANK SIDE
COMPONENT) REMOVAL7INSTALLATION.
RECONNECT all components.
RECORD and REMEMBER this Pinpoint Test Step go to
step 6, then RETURN to Pinpoint Test Step that directed
you here.
RESET PCM to completely clear DTCs.
tr After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No REMOVE jumper wire.
Go to next step.
4
CHECK CONSTANT VOLTAGE AT FTP
SENSOR VEHICLE HARNESS
CONNECTOR
• FTP sensor disconnected.
• Key on, engine off.
• Measure voltage between constant voltage
circuit and FTP sensor ground circuit at
FTP sensor vehicle harness connector.
• Is constant voltage between 4.0 and 6.0
volts?
Yes Go to next step.
No
Constant voltage is out of range.
5 CHECK FTP SIGNAL CIRCUIT FOR
SHORTS TO FTP SENSOR GROUND AND
GROUND CIRCUIT
• Key off.
• FTP sensor disconnected.
• Disconnect PCM. Inspect for damaged or
pushed out pins, correction and loose
wires. Service as necessary.
• Install breakout box. Leave PCM
disconnected.
• Disconnect NGS tester from DLC.
• Measure resistance between Test Pin 62
and Test Pin 91 at breakout box.
• Measure resistance between Test Pin 62
and Test Pins 51 and 103 at breakout box.
• Is each resistance greater than 10,000
ohms?
Yes FTP is shorted to FTP sensor ground or ground circuit in
PCM.
REPLACE PCM.
REMOVE breakout box.
RECONNECT all components.
RERUN OBD Test.
No
SERVICE harness short between FTP signal circuit and
FTP sensor ground or ground circuit.
REMOVE breakout box.
RECONNECT all components.
RESET PCM to completely clear DTCs.
o r After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
6
EVAPORATIVE SYSTEM RE-CHECK
• RESET PCM to completely clear DTCs.
tr After Repair Procedure
• COMPLETE OBD II Drive Mode.
• Is MIL ON?
Yes
ISOLATE pressure leak in evaporative emission system
(vacuum/fuel vapor hose connections, cracked/split
hoses, damaged components.
SERVICE as necessary.
VERIFY symptom no longer exists.
RESET PCM to completely clear DTCs.
tr After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No If detected here from previous step, return to that step and
continue step.
RETURN to Action to Take column of Pinpoint Test Step
that directed you here.
01-01B-73