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.
1990 Lexus ES 250 AutomaticFACTORY OEM SERVICE PROCEDURE
O/D Off Indicator Light
NOTE:
When retrieving transmission trouble codes, ensure overdrive switch is in the ON position.
- Turn ignition switch to the ON position, but do not start engine. Turn O/D switch on. Using a jumper wire, connect terminals TE1 and E1 at TDCL or check connector. See Figure. Read the trouble codes as indicated by the number of flashes of O/D OFF light.
- If no transmission trouble codes are present, the light will blink continuously 2 times per second. Trouble code flashes will be at the rate of one flash per second with longer pauses separating digits and codes. Refer to ES250 AUTOMATIC TRANSMISSION CODE IDENTIFICATION table. Refer to appropriate transmission diagnostic chart. For location of transmission components, see Fig 1.
- If a malfunction is encountered with transmission and no diagnostic codes are set, refer to transmission diagnostic charts located at rear of ES250 diagnostic charts. These charts will diagnose the following malfunctions:
- No shifting
- Shift point too high or too low
- No upshift to overdrive (after warm-up)
- No lock-up (after warm-up)
To clear codes, see CLEARING CODES in this article.
NOTE:
If both speed sensors No. 1 and No. 2 fail simultaneously, no diagnostic code will be set and fail-safe system will not function. After this occurs, when driving in D range, transmission will not upshift from first gear, regardless of vehicle speed.
ES250 AUTOMATIC TRANSMISSION CODE IDENTIFICATION
| Code (1) | Signal Affected | ||||
|---|---|---|---|---|---|
| N/A | (2) Normal | ||||
| 42Β | Speed Sensor No. 1 Signal | ||||
| 61Β | Speed Sensor No. 2 Signal | ||||
| 62Β | Solenoid Valve No. 1 Signal | ||||
| 63Β | Solenoid Valve No. 2 Signal | ||||
| 64Β | Lock-Up Solenoid Signal | ||||
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Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
