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.
Power Circuit Inspection
2017 Kia Rio EX, 4D HatchbackSECTION Power Circuit Inspection
■ Open or Short Check
- Ignition "OFF".
- Disconnect Brake Lamp Relay (HAC relay).
- Ignition "ON" & Engine "OFF".
- Measure voltage between power terminal of brake lamp relay (HAC relay) harness connector and chassis ground
Specification: Approx. B+
- Is the measured value within specifications?
YES
- Go to "Control Circuit Inspection" procedure below.
NO
- Check for open or blown fuse referring to "Circuit Diagram" above.
- Repair open or short in power circuit between battery and HECU harness connector and then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Control Circuit Inspection
■ Open Check
- IG "OFF".
- Disconnect Brake Lamp Relay (HAC relay) and HECU connector.
- Measure resistance between monitoring terminal of brake lamp relay (HAC relay) harness connector and brake lamp control terminal of HECU harness connector.
Specification: Approx. below 1Ω
- Is the measured value within specifications?
YES
- Go to "Short Check" procedure below.
NO
- Repair open in control circuit between the brake lamp relay and HECU and then, Go to "VERIFICATION OF VEHICLE REPAIR " procedure.
■ Short Check
- IG "OFF".
- Disconnect Brake Lamp Relay (HAC relay) and HECU connector.
- Measure resistance between control terminal of brake lamp relay (HAC relay) harness connector and chassis ground.
Specification: Infinite (∞ Ω)
- Is the measured value within specifications?
YES
- Substitute with a known-good Brake Lamp Relay (HAC relay) and check for proper operation. If problem is corrected, replace Brake Lamp Relay (HAC relay) and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Repair short in control circuit between Brake Lamp Relay (HAC relay) and HECU, and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
RENDER: 1.0x
NO RELATED
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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.