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.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSHYUNDAI1991SONATA V6-3.0LREPAIR AND DIAGNOSISRELAYS AND MODULESRELAYS AND MODULES - POWERTRAIN MANAGEMENTRELAYS AND MODULES - COMPUTERS AND CONTROL SYSTEMSTECHNICAL SERVICE BULLETINSALL TECHNICAL SERVICE BULLETINSECU - TESTING PRECAUTIONS
1991 Hyundai Sonata V6-3.0L
ECU - Testing Precautions
1991 Hyundai Sonata V6-3.0LSECTION ECU - Testing Precautions
Group: ENGINE ELECTRICAL
Number: 92-36-005
Date: DECEMBER, 1992
Model: ALL
Subject:
ECU TESTING PRECAUTIONS
This bulletin is issued to remind Hyundai technicians NOT to use a test light when checking computer controlled circuits. Use a Digital Volt-Ohm Meter (DVOM) whenever checking the voltage in any computer controlled circuit. Never use a test light to check any computer circuit.
Electronic Control Units that have been replaced under warranty and returned for analysis usually have burnt transistors. Burned transistors are usually caused by high current demands when a test light is utilized to check for voltage in computer circuits. Test light bulbs draw a considerable amount of current in order to light. In most cases, the current demands of a test light will overload the solid-state components (transistors) causing damage.
A DVOM (Digital Volt-Ohm Meter) is the method preferred and recommended by Hyundai for use in the testing of computer circuits. However, Light Emitting Diode (L.E.D.) Testers (logic probe) or lab type oscilloscope may be used to perform some tests as these devices draw small amounts of current through the circuit being tested.
Number: 92-36-005
Date: DECEMBER, 1992
Model: ALL
Subject:
ECU TESTING PRECAUTIONS
This bulletin is issued to remind Hyundai technicians NOT to use a test light when checking computer controlled circuits. Use a Digital Volt-Ohm Meter (DVOM) whenever checking the voltage in any computer controlled circuit. Never use a test light to check any computer circuit.
Electronic Control Units that have been replaced under warranty and returned for analysis usually have burnt transistors. Burned transistors are usually caused by high current demands when a test light is utilized to check for voltage in computer circuits. Test light bulbs draw a considerable amount of current in order to light. In most cases, the current demands of a test light will overload the solid-state components (transistors) causing damage.
A DVOM (Digital Volt-Ohm Meter) is the method preferred and recommended by Hyundai for use in the testing of computer circuits. However, Light Emitting Diode (L.E.D.) Testers (logic probe) or lab type oscilloscope may be used to perform some tests as these devices draw small amounts of current through the circuit being tested.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.