Powertrain Controls - ECM/PCM

Low Ratio Diagnostic Chart:

Shift Solenoid "B" Circuit:

Circuit Description:
The shift solenoids are used inside the valve body to control spool valves, which determine the transmission gear.

Fused ignition power is supplied to solenoid "B". The PCM/TCM will engage "B" by grounding CKT 1223 to energize the solenoid. Code 86 will set when:

^ Vehicle speed is above 7 mph.
^ TPS is more than 25%.
^ PCM/TCM commands 1st or 2nd gear.
^ Trans ratio indicates trans is in 3rd or 4th gear.
^ Conditions met for 6 seconds.

Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test determines if transmission is receiving a solenoid "B" "ON" command.

Diagnostic Aids:
^ Testing and Inspection