Powertrain Controls - ECM/PCM

Diagnostic Trouble Code (DTC) 81:

Transmission Shift Solenoid Circuit:

Legal Shift Solenoid Combinations:

CIRCUIT DESCRIPTION
The 2-3 shift solenoid is used to control fluid flow acting on the 2-3 shift valves. The solenoid is a normally open exhaust valve that is used with the 1-2 shift solenoid to allow four different shifting combinations. The solenoid is attached to the control valve body within the transmission. Ignition voltage is supplied directly to the 2-3 shift solenoid. The Powertrain Control Module (PCM) controls the solenoid by providing the ground path through CKT 1223.

DTC 81 WILL SET WHEN
The PCM commands the solenoid "ON" and voltage remains high (B+) for 2 seconds. The PCM commands the solenoid "OFF" and voltage remains low (zero volts) for 2 seconds.

ACTION TAKEN (PCM WILL DEFAULT TO)
If the solenoid is shorted "OFF" third gear only will occur. If the solenoid is shorted "ON" second gear only will occur. Diagnostic Trouble Code (DTC) 81 will be stored in the PCM memory but will not turn "ON" the Malfunction Indicator Lamp (MIL).

DTC 81 WILL CLEAR WHEN
The fault condition(s) no longer exist, and the ignition switch is cycled "OFF" then "ON."

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test checks 2-3 shift solenoid and the internal transmission wiring for shorts.
2. This test checks for power to 2-3 shift solenoid from the ignition through the fuse.

DIAGNOSTIC AIDS
Check all connections at the transmission.

An open in the ignition feed circuit can cause multiple DTCs to set.