U016A: Lost Communication With Global Positioning System Module

What it means

ECU lost CAN communication with the GPS module. Position-dependent functions (navigation, geofencing) degraded.

At a glance

• Usually lights the warning light of the system that lost communication

How it works

The GPS module supplies position data used by navigation and other position-dependent vehicle functions, and communicates with other modules over the CAN network. U016A is set when the ECU does not receive expected GPS-module messages; loss of module power, gateway routing trouble, or a CAN network fault can interrupt them, but the code alone does not confirm a termination-resistor failure.

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

• Multiple warning lights may illuminate
• Affected modules may go into limp mode or shut down
• Specific functions inoperative depending on module
• Diagnostic tools may show communication faults

How to diagnose it

1. Scan all modules and review freeze-frame data to identify which ECU stored U016A and whether other modules have communication faults.
2. Check which GPS-dependent functions are unavailable and whether the GPS module responds to a full-module scan.
3. Inspect GPS-module power, ground, CAN wiring, and connectors for loose contacts, corrosion, damage, or water entry.
4. Test module power and ground under load against the manufacturer's specification, and check battery condition if low voltage is recorded.
5. Test CAN communication and gateway routing using the vehicle's wiring information; assess bus termination only if the network design and diagnostic procedure call for it.

Common fixes

• Secure or clean a loose or corroded GPS-module connector.
• Repair damaged power, ground, or CAN wiring at the GPS module.
• Restore a failed module supply or ground connection.
• Correct gateway routing if tests show the GPS messages are not being passed correctly.
• Repair a confirmed network termination fault or replace the GPS module only after the relevant circuits pass testing.

Can I keep driving?

If only navigation or other position-dependent features are affected, basic driving is generally possible, but do not rely on GPS-based guidance or location functions. If multiple modules report communication faults or vehicle systems behave abnormally, limit driving and arrange prompt diagnosis.