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.
1988 Isuzu Trooper II Base, StandardFACTORY OEM SERVICE PROCEDURE
TCU Code 6 - Throttle Position Sensor Signal
- Pull water shield cover back from TPS connector. Do not disconnect. With ignition on, check voltage between REd wire and Black wire. Voltage should be 4.5-5.5 volts
- Switch positive lead of voltmeter to White wire. With throttle at idle, reading should be higher than 4 volts. At wide open throttle the reading should be less than 2 volts. Difference of readings between idle and wide open throttle should be 2.6-4.6 volts.
- TPS is adjustable. If adjustment will not bring correct voltage readings, replace TPS.
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:
- • 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.