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Home >> Geo >> 1990 >> Prizm Base, 4D Hatchback, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Computerized Engine Controls >> Electronic Control Module (ECM) >> Power Circuit Checks
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Power Circuit Checks

Using DVOM, check power circuits to ECM for opens or shorts. See appropriate wiring diagram in WIRING DIAGRAMS article.

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.