Mazda CX-7 2007 Workshop Manual page 1453

STEP
• Measure battery voltage.
5
• Is battery voltage okay?
Standard
With ignition switch ON: 11.5 V or more
At idling: 12.5 V or more
Note
• Inspect that battery cables are connected
to terminals securely.
• Is noise occurring only when vehicle
6
electrical system (e.g. fuel pump) operates?
Note
• Identify subject electrical component by
disconnecting fuse, turning switch ON &
OFF, or disconnecting & connecting
connector.
• It will be easy when simulation function on
M-MDS is used.
• Inspect power supply, ground condition, and
7
noise prevention capacitor for electrical
component.
• Is noise present after inspection?
Note
• Inspect following:
— Power supply to electrical component
for voltage drop (compare with battery
voltage)
— Resistance between ground of
electrical component and body.
(Should be close to 0 ohm)
— Installation condition of noise
prevention capacitor for fuel pump etc.
• Inspect antenna plug connection condition.
8
• Is connection okay?
• Turn ignition switch to LOCK position.
9
• Measure continuity between antenna feeder
axis and ground.
• Is there any continuity?
• Compare reception with other audio unit on
10
same model (model/unit) under same
problem conditions.
• Is reception equivalent between customer's
unit and compared unit?
• Retighten ground fixation for antenna
11
installation part and antenna amplifier.
Retighten antenna rod.
• Is noise present, after retightening?
Note
• When antenna is not grounded perfectly,
FM particular noise is likely to be
conspicuous.
End Of Sie
SYMPTOM TROUBLESHOOTING [RADIO]
INSPECTION
Yes Go to the next step.
No Charge battery. Inspect charging system, and repair or
replace if necessary.
Yes Go to the next step.
No Go to the Step 8.
Yes Go to the next step.
No Troubleshooting completed.
Yes Go to the next step.
No Insert antenna plug securely.
Yes Replace antenna feeder.
No Go to the next step.
Yes The system is normal (It is caused by electronic jamming
from outside, or inferior broadcasting station signal
condition).
No Go to the next step.
Yes Replace audio unit.
No Troubleshooting completed.
ACTION
09-03E–7
09-03E