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.
1997 Lexus SC 400FACTORY OEM SERVICE PROCEDURE
System Testing: Notes
NOTE:
Unless specified otherwise, use a DVOM with a minimum input impedance of 10-megohms. For electrical component locations, see ELECTRICAL COMPONENT LOCATIONS .
Identify symptom and perform corrective action as necessary. See SYSTEM TESTS INDEX & TROUBLE SHOOTING GUIDE table.
SYSTEM TESTS INDEX & TROUBLE SHOOTING GUIDE
| Component | Symptom | Action Or TEST No. |
|---|---|---|
| All Meters, Gauges & Lights | No Display At All | TEST 1: . |
| " | 4 Indicator Needles Do Not Illuminate | Replace Circuit Plate |
| " | One Indicator Needle Does Not Illuminate | TEST 2: . |
| " | Entire Face Does Not Illuminate | Replace Circuit Plate |
| " | Face Not Illuminated At One Or More Locations | TEST 3 . |
| " | Brightness Does Not Change With Lights In OFF Or TAIL | TEST 4 . |
| " | Brightness Does Not Change When Rheostat Is Turned | TEST 5 . |
| " | Brightness Remains Dim With Light Switch OFF | Replace Circuit Plate |
| " | Brightness Does Not Go Out When Starter Is Operated | TEST 6 . |
| Speedometer | Does Not Operate While Driving | TEST 7 . |
| " | Display Is Faulty | Replace Meter |
| " | Vehicle Speed Sensor (VSS) Signal Faulty | TEST 8 . |
| Tachometer | Does Not Operate | TEST 9 . |
| " | Display Is Faulty | Replace Meter |
| Fuel Gauge | Does Not Operate Or Operation Is Abnormal | TEST 10 . |
| Fuel Level Warning | Warning Does Not Illuminate Or Always Illuminated | TEST 11 . |
| Engine Coolant Temp. Gauge | Does Not Operate Or Operation Is Abnormal | TEST 12 . |
| Odometer & Twin Trip Meter | Display Does Not Change While Driving | TEST 13 . |
| " | Display Is Reset When Ignition Turned Off | TEST 14 . |
| " | Abnormal Display | Replace Odo& Twin Trip Meter |
| Outside Air Temp. Display | Abnormal Display | TEST 15 . |
| Engine Oil Level Warning | Warning Does Not Illuminate | TEST 16 . |
| " | Warning Always Illuminated | TEST 17 . |
| Transmission PWR Indicator | Abnormal Operation Or Indicator Does Not Illuminate | TEST 18 . |
| CRUISE MAIN Indicator | Abnormal Operation Or Indicator Does Not Illuminate | TEST 19 . |
| O/D OFF Indicator | Abnormal Operation Or Indicator Does Not Illuminate | TEST 20 . |
| Shift Position Indicator | Abnormal Operation Or Indicator Does Not Illuminate | TEST 21 . |
| TRAC OFF Indicator | Abnormal Operation Or Indicator Does Not Illuminate | TEST 22 . |
| ABS Warning | Abnormal Operation Or Warning Does Not Illuminate | TEST 23 . |
| Hi-Beam Indicator | Abnormal Operation Or Indicator Does Not Illuminate | TEST 24 . |
| Turn Signal Indicator | Abnormal Operation Or Indicator Does Not Illuminate | TEST 25 . |
| Window Washer Warning | Abnormal Operation Or Warning Does Not Illuminate | TEST 26 . |
Factory Service Tools
Use the Manual With the Right Hardware
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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.