U0127: Lost Communication with Tire Pressure Monitor Module

What it means

A control module has stopped receiving expected messages from the tire pressure monitor module. Tire-pressure monitoring may be unavailable or may show a system fault.

How it works

The tire pressure monitor module collects or relays information used to report tire pressures and system status. Other modules expect it to send messages over the vehicle network. U0127 sets when those messages are not received, so pressure readings or the TPMS system status may be unavailable.

Common causes

Most likely first.

1. Tire pressure monitor module power or ground fault
2. Damaged network wiring or connector
3. Tire pressure monitor module failure
4. Low system voltage

Symptoms

• TPMS warning or system fault message
• Tire-pressure readings may be unavailable
• Other communication codes

How to diagnose it

1. Check all tires with a reliable pressure gauge and compare them with the vehicle’s placard, since a communication fault can prevent the display from warning about an underinflated tire.
2. Scan the vehicle for related TPMS, network, and low-voltage codes and save freeze-frame data before clearing anything.
3. Check battery condition and charging-system operation for a low-voltage cause affecting module communication.
4. Inspect the tire pressure monitor module’s connector, power and ground wiring, and network harness for damage, corrosion, or looseness.
5. If the module has power and ground but is offline, test its network circuits against the wiring diagram and manufacturer’s specification.

Common fixes

• Set tire pressures to the vehicle placard values and correct any leaks found.
• Correct a weak battery or charging-system fault.
• Reconnect or clean a loose or corroded TPMS module connection.
• Repair damaged network wiring or restore the module’s power or ground.
• Replace the tire pressure monitor module if its circuits are sound but it does not communicate.

Can I keep driving?

You can generally drive if the tires are in good condition and set to the specified pressures, but the TPMS may not warn you about pressure loss. Check tire pressures manually until the system is working again.