Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2011 Mazda 3 L4-2.5LFACTORY OEM SERVICE PROCEDURE
Component Tests and General Diagnostics
KEYLESS CONTROL MODULE INSPECTION
1. Remove the following parts:
a. Passenger-side front scuff plate Front Scuff Plate Removal/Installation
b. Passenger-side front side trim Front Side Trim Removal/Installation
c. Grove compartment Service and Repair
d. Passenger-side lower panel Lower Panel Removal/Installation
2. Measure the voltage according to the terminal voltage table.
- If the voltages cannot be verified as indicated in the terminal voltage table, inspect the parts under "Inspection item (s)".
- If the system does not work normally even though the inspection items or related wiring harnesses do not have any malfunction, replace the keyless control module.
Terminal Voltage Table (Reference)
*1
MTX
*2
ATX
*3
5HB
Generated pulse (reference)
Pattern 1
- Terminal:
- Starter relay: 2F (+) -> body ground (-)
- Starter relay: 3B (+) -> body ground (-)
- Oscilloscope setting: 2 V/DIV (Y), 1 ms/DIV (X), DC range
Pattern 2
- Terminal:
- Starter relay: 2F (+) -> body ground (-)
- Starter relay: 3B (+) -> body ground (-)
- Starter cut relay/TR switch: 3T (+) -> body ground (-)
- Oscilloscope setting: 2 V/DIV (Y), 1 ms/DIV (X), DC range
Pattern 3
- Terminal:
- Door lock-link switch (driver's door): 4U (+) -> body ground (-)
- Oscilloscope setting: 2 V/DIV (Y), 1 ms/DIV (X), DC range
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
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