P0561

ALLISON AUTOMATIC TRANSMISSION

DTC P0561

DTC P0561 Step 1 - 2:

DTC P0561 Step 3 - 10:

Circuit Description for Allison Automatic Transmission
The Transmission Control Module (TCM) requires ignition voltage to operate correctly. DTC P0561 is a type C DTC.

Conditions for Running the DTC
^ The components are powered and ignition voltage is greater than 9.0 V and less than 18 V.
^ Engine is greater than 400 RPM for 0.5 second.

Conditions for Setting the DTC
DTC P0561 sets when the TCM detects unrealistic variations in ignition voltage over the entire range of voltage.
^ When voltage drops below 6.5 V at either Force Motor (TCM Driver) or ignition input for 1.5 seconds
^ When the voltage variation limit of 4 V or over is detected at either the TCM or ignition input.

Action Taken When the DTC Sets
^ The TCM does not illuminate the Malfunction Indicator Lamp (MIL).
^ Transmission fails to hydraulic default.
^ DTC P0561 will be stored in TCM history.
^ The TCM inhibits TCC engagement.

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

Diagnostic Aids
^ Inspect for aftermarket devices that could offset the operation of the Start and Charge System.
^ Inspect the wiring for poor electrical connections at the TCM. Look 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 fault.

Test Description
The number(s) refer to the step numbers) on the diagnostic table.
3. This step checks battery feed.
4. This step checks ignition failure.
7. This step checks accessories for voltage fluctuation.