4L80E Automatic Transmission

DTC 86:

Ratio Circuit:

CIRCUIT DESCRIPTION
The shift solenoids are used inside the valve body to control spool valves. The shift solenoids determine the transmission gear.
Fused ignition power is supplied to 2-3 solenoid. The PCM/TCM will engage 2-3 solenoid by grounding CKT 1223 to energize the 2-3 solenoid.

Code 86 will set when:
^ Vehicle speed is above 7 mph.
^ TPS is more than 25%.
^ PCM/TCM commands 1st or 2nd gear.
^ Transmission ratio indicates transmission 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 2-3 shift solenoid "ON" command.

DIAGNOSTIC AIDS
Refer to Diagnosis By Symptom Testing and Inspection