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.
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HOMESERVICE MANUALSTOYOTA19904RUNNER 2D UTILITY, 3.0 V, STANDARDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 20 (ENGINE CONTROLS - TESTS W/CODES)RETRIEVING TROUBLE CODES
1990 Toyota 4Runner 2D Utility, 3.0 V, Standard
Retrieving Trouble Codes
1990 Toyota 4Runner 2D Utility, 3.0 V, StandardSECTION Retrieving Trouble Codes
WARNING: This page is about a different car, the 1990 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
DO NOT
enter self-diagnostic system until all basic engine checks (engine, fuel and spark) have been performed. See the BASIC TESTING
article in this section.
- Verify "CHECK ENGINE" light circuit is operational. Ensure battery voltage is above 11 volts and charging system is okay. Engine must be at normal operating temperature.
- Transmission/transaxle must be in Neutral or Park. Air conditioner and other accessories must be off. Throttle valve must be closed (throttle position idle contacts closed).
- Turn ignition switch to "ON" position with engine off. Place jumper wire across "TE1" (or "T") and "E1" terminals in engine check connector. See Fig 1.
- Count number of flashes from "CHECK ENGINE" light. If system is operating properly (with no codes), "CHECK ENGINE" light will blink continuously and evenly. See Fig 2.NOTE: If "CHECK ENGINE" light stays on and will not blink codes, verify battery voltage is present at "TE1" (or "T") with key on and engine off. Ensure "E1" has continuity to ground or self-diagnostics will not work. If ground ("E1") is open, jumper "TE1" (or "T") to battery ground.
- A trouble code will be identified by a .5 second flash on and off for the first number. A 1.5 second pause will occur followed by the second number. See Fig 2.
- If more than one code is stored, a 2.5 second pause will occur before second code is flashed. Once all codes have been displayed, a 4.5 second pause will occur and code(s) will repeat.
- Trouble codes are given from smallest number code to largest number code. After codes are retrieved, remove jumper wire to exit diagnostic mode.
RENDER: 1.0x
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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.