1990 Geo Tracker Base, StandardFACTORY OEM SERVICE PROCEDURE

ECM Circuit Resistance

Before installing ECM, resistance of designated circuits should be checked or ECM may be damaged. See ECM CIRCUIT RESISTANCEΒ  table. Check resistance with ignition off, connector installed on components and connector removed from ECM.

ECM CIRCUIT RESISTANCE

Circuit (1) ECM Connector Terminals (Wire Colors) Ohms
Control Relay G16-G11 (Pink & Black/Yellow) 114-140
EGR & Throttle Opener VSV G5-G14 (Lt. Green/Yellow Lt. Green/White) 70-80
Fuel Injector G8-G17 (Red & Yellow) 1-2
ISC Solenoid Valve G6-G15 (Lt. Green & Black/Blue) 5-7
Lock-Up Relay & PTC Heater Relay Y10-Y11 (White/Blue & White/Yellow) 180-220
(1) For ECM terminal identification, see appropriate wiring diagram in WIRING DIAGRAMS article.
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:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.