Mazda MX-6 1998, Workshop Manual

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TROUBLESHOOTING [ENGINE CONTROL FS]
STEP INSPECTION ACTION
7 CHECK CDCV MECHANICAL OPERATION
OPEN VACUUM POSITION
• Key off.
• Disconnect vacuum hose at both ends of
CDCV.
• If CDCV is directly attached to charcoal
canister, disconnect fuel vapor hose from
purge solenoid valve to charcoal canister at
charcoal canister.
• Install hand-held vacuum pump vent to
atmosphere side of CDCV.
• CDCV electrically connected.
• Apply 53 kPa {0.53 kgf/cm2, 16 inHg} of
vacuum to CDCV.
• Does CDCV hold vacuum for one
minute?
Yes REMOVE vacuum pump.
REPLACE CDCV.
RECONNECT all components.
RESET PCM completely clear DTCs.
tr After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No RECONNECT all components.
Go to next step.
8 CHECK CDCV RESISTANCE
• Key off.
• Disconnect CDCV harness connector.
• Measure the resistance between CDCV
terminals.
• Is each resistance less than 45 ohms?
Yes CDCV circuit is shorted to ground in CDCV.
REPLACE CDCV.
RECONNECT all components.
RESET PCM completely clear DTCs.
t? After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No Go to next step.
9
CHECK CDCV CIRCUIT FOR SHORT TO
GROUND CIRCUIT
• Key off.
• CDCV disconnected.
Yes
Go to next step.
• Disconnect PCM. Inspect for damaged or
pushed out pins, corrosion and loose wires.
Service as necessary.
• Install breakout box. Leave PCM
disconnected.
• Disconnect NGS tester from DLC.
• Measure resistance between Test Pin 67
and Test Pins 51 and 103 at breakout box.
• Is each resistance greater than 10,000
ohms?
No SERVICE harness short between CDCV and ground.
REMOVE breakout box.
RECONNECT all components.
RESET PCM completely clear DTCs.
uy After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
10 INSPECTION OF FUEL TANK
• Remove and inspect fuel tank.
• Is fault detected?
Yes SERVICE or REPLACE fuel tank or sealing.
RECONNECT all components.
RESET PCM completely clear DTCs.
ter After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No UNABLE to duplicate or identify fault.
Go to ENGINE SYMPTOM TROUBLESHOOTING No.30.
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