Mazda 3 - Fuel Pump Operation Inspection; Fuel Pump Control System Inspection

Mazda 3 Workshop Manual – Engine + Wiring Diagrams + Diagnostic Trouble Codes
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4. Access RPM and FUELPW1 PIDs.
5. Monitor both PIDs while performing the following steps.
(1) Depress the accelerator pedal and increase the engine speed to 4,000 rpm.
(2) Release the accelerator pedal (brake pedal is not depressed) and verify that the fuel injector
duration time is 0 ms., and 2-5 ms. when the engine speed drops below 1,300 rpm.
• If not as specified, inspect the following.
- ECT sensor and related wiring harness (See ENGINE COOLANT TEMPERATURE (ECT)
SENSOR INSPECTION [LF].)
- Neutral/clutch pedal position switch and related wiring harness (See CLUTCH PEDAL
POSITION (CPP) SWITCH INSPECTION [LF].)
Fuel Pump Operation Inspection
1. Connect the WDS or equivalent to the DLC-2.
2. Remove the fuel-filler cap.
3. Turn the ignition switch to the ON position.
4. Turn the fuel pump relay from off to on using the FP PID and inspect if the operation sound is heard.
• If no operation sounds is heard, proceed to next step.
5. Measure the voltage at wiring harness-side fuel pump terminal A.
Specification
B+ (Ignition switch is ON position)
• If the voltage is as specified, inspect the following.
- Fuel pump continuity
- Fuel pump GND
- Wiring harness between fuel pump relay and PCM terminal 1AQ (without immobilizer system),
1AR (with immobilizer system)
• If not as specified, inspect the following.
- Fuel pump relay (See RELAY INSPECTION.)
- Wiring harness and connector (Main relay-fuel pump relay-fuel pump)
Fuel Pump Control System Inspection
1. Connect the WDS or equivalent to the DLC-2.
2. Turn the ignition switch to the ON position.
3. Access FP PID.
4. Turn the fuel pump relay from off to on and inspect if the operation sound of the fuel pump relay is
heard.
• If no operation sound is heard, inspect the fuel pump relay.