Code 87, Shift Solenoid "B" Stuck "Off": Notes

The shift solenoids are used inside the valve body to control spool valve position, which determines the transmission gear. Fused ignition power is supplied to solenoid "B." The PCM/TCM will engage solenoid "B" by grounding circuit No. 1223 to energize the solenoid.

Code 87 will set under the following conditions.

Vehicle speed is greater than 7 MPH.
TPS is more than 25 percent.
PCM/TCM commands 3rd or 4th gear.
Transmission ratio indicates transmission is in 1st or 2nd gear.
Conditions are met for 6 seconds.

NOTE: Test numbers refer to test numbers on diagnostic chart.

This test checks PCM/TCM's ability to ground or control solenoid "B". If bidirectional Scan tester is not available, solenoid may be activated by grounding ALDL test terminal "B" with ignition on and engine off.
This test checks the power supply and circuit No. 1223.
This test checks the internal transmission harness and solenoid "B".