1990 Infiniti M30FACTORY OEM SERVICE PROCEDURE

Crank Angle & Sub-Crank Angle Sensor Signal

  1. Remove crank angle sensor from engine. Do not disconnect crank angle sensor harness connector. Turn ignition switch on, engine off.
  2. Connect negative voltmeter lead to ground. Rotate crank angle sensor shaft slowly by hand. Connect positive voltmeter lead to crank angle sensor connector terminal No. 1 (90-degree signal), voltage should fluctuate between 0-5 volts. Move voltmeter positive lead to terminal No. 2 (one-degree signal), voltage should also fluctuate between 0-5 volts. See Fig 1 .
    Fig 1: Checking Q45 Crank Angle & Sub-Crank Angle Sensors Circuits
    G90C18749Courtesy of NISSAN MOTOR CORP., U.S.A.
  3. Set voltmeter to 100 mV AC scale. Connect positive voltmeter lead to terminal "a" and negative voltmeter lead to terminal "b" of sub-crank angle sensor terminal connector. See Fig 1 . Rotate crank angle sensor shaft slowly by hand, voltmeter should deflect. If voltmeter does not deflect, replace crank angle sensor.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.