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.
Problem Symptoms Table
HINT:
If a normal system code is displayed during the DTC check but the problem still occurs, check the circuits for each problem symptom in the order given in the table below and refer to the relevant troubleshooting area, For details refer to the "See" below.
| Symptom | Suspected Area | See |
|---|---|---|
| Engine switch does not turn on (IG and ACC) | 1. Smart key system operation inspection (on the seat) | Refer to ON-VEHICLE INSPECTION |
| 2. AM1 and AM2 circuit (B2271) | Refer to DTC B2271: Ignition Hold Monitor Malfunction | |
| 3. Engine switch circuit (B2278) | Refer to DTC B2278: Engine Switch Circuit Malfunction | |
| 4. Ground circuit (Power source control ECU - Body ground) | Refer to TERMINALS OF ECU | |
| 5. Replace power source control ECU | - | |
| Engine switch does not turn on (ACC) | 1. AM1 and AM2 circuit (B2271) | Refer to DTC B2271: Ignition Hold Monitor Malfunction |
| 2. ACCD circuit (B2274) | Refer to DTC B2274: ACC Monitor Malfunction | |
| 3. Ground circuit (Power source control ECU - Body ground) | Refer to TERMINALS OF ECU | |
| 4. Replace power source control ECU | - | |
| Engine switch does not turn on (IG) | 1. AM1 AM2 circuit (B2271) | Refer to DTC B2271: Ignition Hold Monitor Malfunction |
| 2. IG1D circuit (B2272) | Refer to DTC B2272: Ignition 1 Monitor Malfunction | |
| 3. IG2D circuit (B2273) | Refer to DTC B2273: Ignition 2 Monitor Malfunction | |
| 4. Ground circuit (Power source control ECU - Body ground) | Refer to TERMINALS OF ECU | |
| 5. Replace power source control ECU | - | |
| Engine switch does not turn on (START) | 1. Stop light switch circuit (B2284) | Refer to DTC B2284: Brake Signal Malfunction |
| 2. Starter relay circuit | Refer to Starter Relay Circuit | |
| 3. SFI system | Refer to PROBLEM SYMPTOMS TABLE | |
| 4. Replace power source control ECU | - | |
| Engine switch indicator light does not come on | Engine switch indicator light circuit | Refer to Engine Switch Indicator Circuit |
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.