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.

2005 Toyota MR2 C56FACTORY OEM SERVICE PROCEDURE

Circuit Opening Relay: Inspection

REMOVE CIRCUIT OPENING RELAY (Marking: C/OPN)

Fig 1: Removing Circuit Opening Relay
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT CIRCUIT OPENING RELAY

Inspect the resistance.
1. Using an ohmmeter, measure the resistance between the terminals.
Standard:

CIRCUIT OPENING RELAY - TESTER CONDITION TABLE

Tester Connection	Specified Condition
3-5	10 kΩ or higher
3-5	Below 1Ω (Apply battery voltage to terminals 1 and 2)

If the resistance is not as specified, replace the relay.

REINSTALL CIRCUIT OPENING RELAY

Fig 2: Measuring Resistance Between Terminals Using An Ohmmeter
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready Tools Compare Repair Quote Quote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.