1993 Nissan-Datsun Sentra SE-R, AutomaticFACTORY OEM SERVICE PROCEDURE

Fast Idle Control Device (FICD) System Test (Quest)

  1. Start engine and warm to operating temperature. Check idle speed. See SPECIFICATIONS article. Adjust idle speed if necessary. See ADJUSTMENTS article. Turn air conditioning and blower fan switches on. Idle speed should increase. If idle speed does not increase, go to next step. If idle speed increases, system is functioning properly.
  2. Ensure air conditioner compressor is functioning. If compressor is not functioning, repair air conditioner system as necessary. If compressor is functioning, turn ignition off. Disconnect FICD relay. Relay is located in relay box on right front inner fender rail.
  3. Turn ignition on. Measure voltage between ground and FICD relay harness connector terminals No. 2 (Blue wire) and No. 5 (Blue wire). For connector identification, see Figure . Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check 10-amp fuse located in main fuse box under left side of instrument panel. If fuse is okay, repair open in harness between fuse and FICD relay.
  4. Turn ignition off. Disconnect FICD solenoid harness connector. Check continuity between ground and FICD solenoid harness connector Black wire. Check continuity between FICD solenoid harness connector Blue/Yellow wire and FICD relay harness connector terminal No. 3 (Blue/Yellow wire). Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in Blue/Yellow wire or connectors.
  5. Turn ignition on. Measure voltage between ground and FICD relay harness connector terminal No. 1 (White/Red wire). With air conditioner switch on and fan switch in any position except off, less than 2.3 volts should be present. With air conditioning switch off, 7-9 volts should be present. If voltage is as specified, go to next step. If voltage is not as specified, repair open in White/Red wire between FICD relay harness connector and air conditioner system.
  6. Check FICD relay. See RELAYS under RELAYS & SOLENOIDS  . If relay is okay, check FICD solenoid. See FAST IDLE CONTROL DEVICE (FICD) TEST. If FICD solenoid is okay, check ECM and ECM harness connector terminal No. 41 (White/Red wire) for correct installation, damage or corrosion. Repair or replace as necessary.
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.