B2722

DTC B2722


Circuit Description with 4L80-E / 4L85-E Automatic Transmission
Tow/Haul mode enables the operator to achieve enhanced shift performance when towing or hauling a load. When tow/haul is selected, the tow/haul switch input signal to the body control module (BCM) is momentarily toggled to zero volts. The BCM sends a serial data message to the powertrain control module (PCM) and instrument panel controller (IPC). The PCM extends the length of time between upshifts, increases transmission line pressure and the IPC illuminates the tow/haul indicator lamp. Cycling the tow/haul switch again disables the tow/haul mode and returns the transmission to a normal shift pattern.

Conditions for Running the DTC
^ The battery voltage must be 9 - 16 volts.
^ Ignition switch in the RUN position.
^ The Tow/Haul switch must be activated.

Conditions for Setting the DTC
When the signal circuit of the Tow/Haul switch is shorted to ground for approximately 3 minutes.
When the Tow/Haul switch is activated, stuck, for approximately 3 minutes.

Action Taken When the DTC Sets
Tow/Haul mode will be inoperative.

Conditions for Clearing the MIL/DTC
^ This DTC will clear on current status after the condition for setting the fault is corrected.
^ A history DTC will clear after 100 consecutive ignition cycles without a fault present.
^ History and current DTCs can be cleared using a scan tool.

Diagnostic Aids
^ Perform a visual inspection for loose or poor connections at all related components.








Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. The normal state is the state of the input before activation.
4. The normal state is the state of the input before activation.
8. After replacement of the BCM you must calibrate the new module for proper operation.