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Home >> Ford >> 1990 >> Bronco II 4WD, Standard, M5OD-R1 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Test H - Fuel Control >> Test H: Step 16
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Test H: Step 16

16) Check HEGO Circuit For Short to Ground  Turn key off. Leave breakout box installed and ECA disconnected. Disconnect HEGO sensor and set DVOM on 200-k/ohm scale. Measure resistance between test pin No. 29 and test pins No. 40 and 49 at the breakout box. For trucks equipped with 4-wire sensors, measure resistance between test pin No. 29 and test pins No. 40 and 46 at the breakout box. For vehicles with dual sensors, measure resistance between test pin No. 43 and test pin No. 40. If any reading is less than 10 k/ohms, repair short to ground. Remove breakout box, reconnect all components and repeat QUICK TEST. If reading is 10 k/ohms or more, go to next step.