Allison Automatic Transmission

ALLISON AUTOMATIC TRANSMISSION

DTC P0741

DTC P0741 Step 1 - 5:

Circuit Description for Allison Automatic Transmission
The Transmission Control Module (TCM) uses data from the engine speed sensor and the input speed sensor to calculate torque converter slip value. The TCM then compares this calculated slip value to a preset value in the TCM calibration. DTC P0741 is a type B DTC.

Conditions for Running the DTC
^ DTC P0122 and DTC P0123 are not active.
^ DTC P0716 and DTC P0717 are not active.
^ DTC P0721 and DTC P0722 are not active.
^ DTC P1860 is not active.
^ The components are powered and ignition voltage is greater than 9V and less than 18 V.
^ Engine speed is greater than 200 RPM and less than 7,500 RPM for 5 seconds.
^ The throttle position is in the 10-90 percent range.
^ Must be in forward range.
^ The torque converter clutch is enabled.

Conditions for Setting the DTC
DTC P0741 sets when the TCM detects one of the following conditions:
^ A torque converter clutch slip value greater than 80 RPM for 15 seconds.
^ The torque converter clutch slip speed values indicate a "stuck off" state.

Action Taken When the DTC Sets
^ The TCM illuminates the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
^ DTC P0741 will be stored in the TCM history.
^ The TCM freezes shift adapts (DNA).
^ TCM inhibits TCC engagement.

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

Diagnostic Aids
^ 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 numbers refer to the step numbers on the diagnostic table.
2. This step tests ignition voltage.
3. This step tests for TCC enable status.