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.
Time Control Unit Test
NOTE: The Time Control Unit (TCU) is used on Maxima, Stanza, 240SX and 300ZX models. Control unit operates many different systems for each vehicle. The following circuit test procedures only check circuits that control the wiper delay operation.
When testing time control unit, insert probes into harness side of connector while still plugged into control unit. See Figure and Figure . Ensure ignition key is in correct position when testing each circuit. Perform tests in order:
- Power Circuit
- TCU Output Wiper Relay Circuit
- Wiper Switch Circuit
- Intermittent Wiper Volume
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.