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.
2007 Mazda 3 L4-2.0LFACTORY OEM SERVICE PROCEDURE
Relay Box: Service and Repair
PASSENGER JUNCTION BOX (PJB) REMOVAL/INSTALLATION
1. When replacing the PJB, perform the following.
- PJB configuration (See PASSENGER JUNCTION BOX (PJB) CONFIGURATION.)
2. Disconnect the negative battery cable.

3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
Connector A Removal Note

1. Push the release tab in the direction of the arrow.
2. Rotate the lever in the direction of the arrow and remove connector A.
Connector B Removal Note

1. Rotate the lever in the direction of the arrow and remove connector B.
PJB Removal Note

1. Turn the screws counterclockwise to remove the PJB.
NOTE: Screws cannot be removed from the PJB.

2. Remove the PJB as shown in the figure.
Connector B Installation Note

1. Install the connector B as shown in the figure.
Connector A Installation Note

1. After connecting the connector, rotate the lever in the direction of the arrow to install connector A.
1. When replacing the PJB, perform the following.
- PJB configuration (See PASSENGER JUNCTION BOX (PJB) CONFIGURATION.)
2. Disconnect the negative battery cable.
3. Remove in the order indicated in the table.
4. Install in the reverse order of removal.
Connector A Removal Note
1. Push the release tab in the direction of the arrow.
2. Rotate the lever in the direction of the arrow and remove connector A.
Connector B Removal Note
1. Rotate the lever in the direction of the arrow and remove connector B.
PJB Removal Note
1. Turn the screws counterclockwise to remove the PJB.
NOTE: Screws cannot be removed from the PJB.
2. Remove the PJB as shown in the figure.
Connector B Installation Note
1. Install the connector B as shown in the figure.
Connector A Installation Note
1. After connecting the connector, rotate the lever in the direction of the arrow to install connector A.
Factory Service Tools
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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.
