U019E: Lost Communication With Transmission Range Control Module

What it means

A control module is not receiving expected messages from the Transmission Range Control Module. Gear range information may be unavailable or unreliable; resulting effects depend on the vehicle.

At a glance

• Usually lights the warning light of the system that lost communication
• The engine or gearbox may go into limp mode

How it works

The Transmission Range Control Module reports the selected gear range so other modules can coordinate starting and transmission operation. U019E sets when expected messages from that module are missing, making the reported range unavailable or unreliable.

Common causes

Most likely first.

1. Module unpowered
2. Gateway module routing CAN messages incorrectly
3. CAN terminating resistor (120 Ω) drifted out of spec

Symptoms

• Transmission or gear-selector warning
• Gear selection or starting may be affected
• Other communication codes

How to diagnose it

1. Save freeze-frame data and scan the transmission, engine, and network modules for companion codes before clearing anything.
2. Check whether the gear display agrees with the selector position and whether the vehicle starts only in the expected selector positions.
3. Inspect the range control module's power, ground, connectors, and wiring for loose terminals, corrosion, or damage.
4. Check the network path to the module and look for gateway faults that could block its range messages.
5. Have the communication bus and terminating resistance tested against the manufacturer's specification if basic checks do not find the cause.

Common fixes

• Repair damaged or corroded wiring or connectors at the Transmission Range Control Module.
• Restore the module's power or ground supply and address any blown fuse's underlying cause.
• Correct a gateway routing or configuration problem.
• Repair network wiring or replace the module or a failed terminating resistor after testing confirms the fault.

Can I keep driving?

Do not drive if the displayed gear is wrong, the vehicle will not select or hold a gear, or starting behavior is unpredictable; it could move unexpectedly or become immobilized. If range selection and display seem normal, limit use and arrange prompt diagnosis because limp mode may restrict operation.