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.
General Precautions
- Always use a 12 volt battery as power source.
- Never attempt to disconnect battery cables while engine is running.
- Before connecting or disconnecting the ECM harness connector, turn ignition switch OFF and disconnect battery negative cable. Failure to do so may damage the ECM because battery voltage is applied to ECM even if ignition switch is turned off.
- Before removing parts, turn ignition switch OFF and then disconnect battery negative cable.
- Never disassemble ECM.
- When connecting or disconnecting pin connectors into or from ECM, be careful not to damage pin terminals (bend or break).
Check that there are not any bends or breaks on ECM pin terminal when connecting pin connectors.
- Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge) voltage to develop in coil and condenser, which cause damage to IC's.
- Keep engine control system harness at least 10cm (4 in) away from adjacent harness to prevent engine control system malfunctions from receiving external noise, degraded operation of IC's, etc.
- Keep engine control system parts and harness dry.
- Before replacing ECM, perform ECM Terminals and Reference Value inspection and check that ECM functions normally. Refer to REFERENCE VALUE
.
- Even a slight leakage in the air intake system can cause serious incidents.
- Never shock or jar the camshaft position sensor and crankshaft position sensor.
- When measuring ECM signals with a circuit tester, never allow the two tester probes to contact.
Accidental contact of probes cause a short circuit and damage the ECM power transistor.
- Never disassemble fuel pump.
If NG, take proper action.
- Never disassemble fuel injector.
If NG, replace fuel injector.
- Never depress accelerator pedal when starting.
- Immediately after starting, never rev up engine unnecessarily.
- Never rev up engine just prior to shutdown.
- When installing C.B. ham radio or a mobile phone, always observe the following as it may adversely affect electronic control systems depending on installation location.
- Keep the antenna as far as possible from the electronic control units.
- Keep the antenna feeder line more than 20 cm (8 in) away from the harness of electronic controls.
Never let them run parallel for a long distance.
- Adjust the antenna and feeder line so that the standingwave radio can be kept smaller.
- Always ground the radio to vehicle body.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.
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