P0883

LCT 1000 Allison Transmission

DTC P0883

Circuit Description
The transmission control module (TCM) requires direct battery voltage to operate properly.

DTC P0883 is a type C DTC.

DTC Descriptor
This diagnostic procedure supports the following DTC:

DTC P0883 Transmission Control Module (TCM) Power Input Signal High

Conditions for Running the DTC
Engine speed is greater than 400 RPM for 1 second.

Conditions for Setting the DTC
DTC P0883 sets when the TCM detects battery direct voltage greater than 18 volts for 6 out of 10 seconds.

Action Taken When the DTC Sets
^ The TCM does not illuminate the malfunction indicator lamp (MIL).
^ Hydraulic default is commanded. Shift selector position and hydraulic state of logic valves determine range.
^ The TCM inhibits main modulation.
^ The TCM inhibits torque converter clutch (TCC) engagement.

Conditions for Clearing the MIL/DTC
A scan tool can clear the code from TCM history. The TCM automatically clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without failure.

Diagnostic Aids
^ Inspect the wiring for poor electrical connections at the TCM. Inspect for the following conditions:
^ A bent terminal
^ A backed-out terminal
^ A damaged terminal
^ Poor terminal tension
^ A chafed wire
^ A broken wire inside the insulation
^ When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.
^ You may have to drive the vehicle in order to experience a condition.
^ This DTC is normally set due to vehicle charging system concerns.

Test Description

Step 1 - Step 6:

The numbers below refer to the step numbers on the diagnostic table.
2. This step tests for proper TCM battery direct voltage.
3. This step tests the vehicle charging system.