Mazda MX-6 1998, Workshop Manual

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TROUBLESHOOTING [ENGINE CONTROL FS]
22 VIBRATION CONCERNS (ENGINE)
DESCRIPTION Vibration from under hood or driveline
POSSIBLE
CAUSE
• Loose attaching bolts or worn parts
• Components malfunctioning such as worn parts
STEP
INSPECTION ACTION
1 Check following components for loose
attaching bolts or worn parts:
• Cooling fan.
• Drive belt and pulleys.
• Engine mounts.
All items okay? Yes Check following systems:
• Wheels.
• Transaxle.
• Driveline.
• Suspension.
No Readjust or retighten engine mount installation position.
Service as necessary for other parts.
2 Verify test results. If okay, return to diagnostic index to service any additional symptoms.
23 A/C DOES NOT WORK
DESCRIPTION A/C compressor magnetic clutch does not engage when A/C is turned on
POSSIBLE
CAUSE
• Improper refrigerant charging amount
• Open A/C magnet clutch
• Poor ground of A/C magnet clutch
• A/C relay stuck to open
• Power steering stuck to short
• Open circuit between A/C switch and PCM through both A/C pressure switches
• Short to ground circuit between power steering pressure switch and PCM
• A/C low pressure switch stuck to open
• Open circuit between A/C relay and A/C magnet clutch
• A/C high pressure switch stuck open
• A/C compressor seized
STEP
INSPECTION ACTION
1 Retrieve and record any continuous memory,
KOEO and KOER DTCs.
Are there any DTCs displayed?
Yes
Go to appropriate DTC test.
No
Go to next step.
2 Disconnect power steering pressure switch
connector.
Is there continuity between connector terminal
and ground?
Yes Short to ground.
Repair or replace wire harness.
No
Check for short to ground at power steering pressure
switch.
If switch is okay, go to next step.
If short exists, replace switch.
3 Disconnect A/C compressor connector.
Start the engine and turn A/C switch on.
Is there correct voltage at terminal of A/C
compressor magnet clutch connector?
Specification
More than
10.5
V
Yes Check for ground condition of A/C compressor magnet
clutch.
If ground condition is okay, check for open circuit of
magnet clutch.
No Go to next step.
4 Disconnect A/C low pressure switch and A/C
high pressure switch connectors.
Connect jum per wires between terminals of
harness connectors.
Connect NGS tester to DLC.
Access ACCS PID on NGS tester.
Turn ignition switch ON.
Turn A/C switch on and set blower fan at any
Sp0QCl.
Does ACCS PID read ON?
Yes Check A/C high pressure switch and low pressure switch
operation. Replace malfunctioning switch.
If both switches okay, Go to next step.
No Check following:
• A/C switch stuck open.
• Open circuit among both A/C pressure switches and
PCM.
• Open circuit of blower motor fan switch and resister (if
blower motor does not operate).
5
Remove jumper wires from switch connectors.
Reconnect connectors to both switches.
Start engine and turn A/C switch on.
Verify fan operation.
Do both fans operate? Yes
Check for stuck to open A/C relay.
Replace as necessary.
No Check follows and repair or replace as necessary:
• Refrigerant charging amount.
• Seized A/C compressor.
6
Verify test results. If okay, return to diagnostic index to service any additional symptoms.
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