DTC 87, High Gear Ratio (1993): Notes

Shift solenoids are used inside valve body to control spool valves, which determine the transmission gear. Fused ignition power is supplied to solenoid "B", also referred to as 2-3 shift solenoid. PCM/TCM engages solenoid "B" by grounding circuit No. 1223. DTC 87 will set under following conditions: vehicle speed is greater than 7 MPH, TPS value is greater than 25 percent of total TPS travel, 3rd or 4th gear operation is requested by PCM/TCM, and transmission ratio indicates 1st or 2nd gear. All conditions must be met for 6 seconds.

NOTE: Test numbers refer to numbers on diagnostic chart.

Test Number 1) This step checks if PCM/TCM can control solenoid "B". If bidirectional scan tool is not available, solenoid may be activated by grounding ALDL test terminal "B" with ignition on and engine off.

Test Number 2) Battery supply should be present at PCM/TCM.

Test Number 3) This step checks shift solenoid "B" and circuits inside transmission for shorts.