Mazda Mazda6 - Page 377

TROUBLESHOOTING
F2–225
F2
NO.26 CONSTANT VOLTAGE
A6E408018881228
Diagnostic Procedure
26 CONSTANT VOLTAGE
DESCRIPTION • Incorrect constant voltage.
POSSIBLE
CAUSE
• Constant voltage circuit malfunction
• Accelerator positions sensor or related circuit malfunction
• Fuel pressure sensor or related circuit malfunction
• Boost sensor or related circuit malfunction
• ECT sensor GND circuit malfunction
• MAF/IAT sensor GND circuit malfunction
• IAT sensor No.2 GND circuit malfunction
• Fuel temperature sensor GND circuit malfunction
Note
• Accelerator position sensor, fuel pressure sensor and boost sensor use constant voltage.
STEP INSPECTION RESULTS ACTION
1 Disconnect appropriate sensor connectors
(accelerator position sensor, boost sensor and
fuel pressure sensor) where constant voltage
circuits inspection failed.
Turn engine switch to ON position.
Measure voltage between following appropriate
sensor connector terminals:
• Constant voltage terminal and GND terminal.
Is constant voltage above 6.0 V?
Yes Repair constant voltage circuit short to power in
harness.
No Go to next step.
2 Is voltage across battery terminals above 10.5
V?
Yes Go to next step.
No Inspect charging system.
3 Turn engine switch to OFF.
Leave appropriate sensor connectors
disconnected where constant voltage inspection
failed.
Measure voltage between positive terminal and
GND circuit at appropriate sensor vehicle
harness connector.
Is voltage above 10.5 V and within 1.0 V of
battery voltage?
Yes Go to next step.
No Go to Step 8.
4 Note
• Purpose of this step is to determine if
WDS or equivalent is communicating with
PCM.
Turn engine switch to ON.
Attempt to access ECT PID.
Can ECT PID be accessed?
Yes Go to Step 7.
No Go to next step.
5 Turn engine switch to OFF.
Disconnect accelerator position sensor and
PCM connectors.
Turn engine switch to ON.
Measure voltage between PCM connector
terminals 104 and 53/79.
Is voltage greater than 10.5 V?
Yes Go to next step.
No Repair open circuit between PCM terminal 53/79 and
PCM control relay.
6 Leave accelerator position sensor and PCM
connectors disconnected.
Measure resistance between PCM connector
terminals 104 and 90.
Is resistance greater than 10,000 ohms?
Yes Inspect sensor connector for constant voltage again.
No Repair constant voltage circuit short to GND.
7 Turn engine switch to OFF.
Leave accelerator position sensor
disconnected.Disconnect PCM connector.
Measure resistance between PCM connector 90
and constant voltage circuit at appropriate
sensor connector.
Is resistance less than 5.0 ohms?
Yes Inspect sensor connector for constant voltage again.
No Repair open constant voltage circuit.