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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 DN EVP Sensor & EVR Solenoid >> Test DN: Step 93
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Test DN: Step 93

93) Continuous Memory Code 31 and/or 35: Check EEC-IV Harness  Code 31 indicates an open in the EVP or VREF circuits, or a short to SIG RTN with the engine at idle and at normal operating temperature. Code 35 indicates a short to VREF and/or VPWR, or an open in SIG RTN with the engine at idle and at normal operating temperature.

Using KOEO Continuous Monitor Mode, observe VOM or diagnostic tester for fault indication while grasping harness close to sensor and wiggling, shaking, or bending a small section of EEC-IV harness while working toward dash panel. Wiggle, shake or bend harness from firewall to ECA. If fault is indicated, isolate fault and repair wiring harness as required. Clear codes and repeat QUICK TEST. If fault is not found, go to next step.

Fig 1: EVP Harness Faults
G90J12384