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Home >> Oldsmobile >> 1986 >> Toronado >> Repair and Diagnosis >> Engine Performance >> System >> BCM System, Part II >> ECM Trouble Code Charts - Trouble Shooting >> Code B671, Cruise - Servo Position Sensor Circuit Problem >> Notes
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Code B671, Cruise - Servo Position Sensor Circuit Problem: Notes

Fig 1: Code B671, Cruise - Servo Position Sensor Circuit Problem
G5124
Fig 2: Code B671, Cruise - Servo Position Sensor Circuit
GB0048390
Fig 3: Code B671, Schematic
G201320

Code B671 will set if the ignition is on and the servo position sensor signal is below 3%. During the time the failure is present, the cruise control will be disengaged.

  1. BCM data value BD70 displays servo position. The normal range is above 3%.
  2. Checks to see if fault is due to short or open in the feedback circuits. Normal resistance across the feedback coil should be 15-30 ohms.
  3. Checks to see if open circuit reading is due to servo or circuits.
  4. Checks to see if problem is intermittent. BD70 will not go as low or as high as BS05 because of its mechanical limits of travel; however, it should never go below 3%.