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Home >> Ford >> 1987 >> Bronco II RWD, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> CEC Diagnosing & Testing >> Quick Test >> Key On/Engine Running (KOER) Self-Test >> Code Output
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Code Output

  1. Deactivate SELF-TEST (disconnect jumper wire). Start and run engine at 2000 RPM for 2 minutes to warm up EGO sensor. Turn engine off and wait 10 seconds. Insert jumper to activate SELF-TEST. DO NOT  depress throttle during test unless a Dynamic Response code occurs.
  2. Start engine. The engine ID code will be displayed. On 2.3L, 2.9L and 3.0L engine equipped vehicles, depress and release brake pedal, ONE TIME ONLY, after engine ID code has been displayed. This will test the Brake On/Off (BOO) switch. On pickups equipped with 4.9L and 5.0L engines, steering wheel must be turned 1/2 turn and released after ID code.
  3. Run test. If Dynamic Response code 1 (10 with STAR tester) occurs, briefly accelerate engine to wide open throttle (WOT). The ENGINE RUNNING SELF-TEST service codes will then be displayed. Observe and record all codes.
NOTE: The Engine ID code is 1/2 the number of cylinders (a 2 equals a 4 cylinder engine). Diagnostic tester adds a zero to all single digit readings. A "20" on Diagnostic tester equals a 4 cylinder engine. Some vehicles do not require a brief WOT, they will not display a 1 (10).
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