Mazda MX-6 1998, Workshop Manual

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TROUBLESHOOTING [ENGINE CONTROL FS]
STEP INSPECTION ACTION
5 INSPECTION OF VACUUM HOSES
• Pull slightly on vacuum hoses at purge
solenoid, catch tank and charcoal canister.
• Check for loose connections.
• Visually inspect for improperly connected
and cracked hoses between dynamic
chamber and purge solenoid, purge
solenoid and catch tank and catch tank
and charcoal canister.
• Confirm air-tightness of vacuum hose by
using vacuum pump.
• Is fault detected?
Yes SERVICE or REPLACE as necessary.
RECONNECT all components.
RESET PCM to completely clear DTCs.
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After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No RECONNECT all components.
Go to next step.
6
CHECK FOR PURGE SOLENOID VALVE
STUCK CLOSED OR STUCK OPEN
• Remove the purge solenoid valve.
• Confirm the purge solenoid valve air vents
properly when ON and is air tight when
OFF.
• Is fault detected?
Yes REPLACE purge solenoid valve.
RECONNECT all components.
RESET PCM to completely clear DTCs.
t r
After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No RECONNECT all components.
Go to next step.
7 INSPECTION OF CATCH TANK
• Remove catch tank.
• Visually inspect for cracked catch tank.
• Inspect catch tank for plugging by using
vacuum pump.
• Is fault detected?
Yes REPLACE catch tank.
RECONNECT all components.
RESET PCM to completely clear DTCs.
t r
After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No
RECONNECT all components.
Go to next step.
8 INSPECTION OF CHARCOAL CANISTER
• Remove charcoal canister.
• Visually inspect for cracked charcoal
canister.
• Inspect charcoal canister for plugging by
using vacuum pump.
• Is fault detected?
Yes REPLACE charcoal canister.
RECONNECT all components.
RESET PCM to completely clear DTCs.
t r
After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No
RECONNECT all components.
Go to next step.
9 VERIFY FUEL TANK PRESSURE (FTP)
SIGNAL VOLTAGE
• Clamp on hose on tank side of charcoal
canister.
• Remove filler cap.
• Connect NGS tester.
• Key on, engine off.
• Access FTP V PID.
•
Is FTP V PID values same as
atmospheric pressure (approx. 2.5 V)?
Yes Install the filler cap.
Go to step 13.
No
Install the filler cap.
Go to next step.
10 INDUCE OPPOSITE FTP SIGNAL
• Key off.
• Disconnect FTP sensor.
• Connect jum per wire between the 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 jum per immediately and go
directly to next step.
• Access FTP V PID.
• Is the FTP V PID value between 4.0 and
6.0 volts?
Yes REPLACE damaged FTP sensor.
RECONNECT all components.
RESET PCM to completely clear DTCs.
t r
After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No REMOVE jumper.
Go to next step.
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