U0202: Lost Communication With Door Control Module D

What it means

Communication with Door Control Module D was not received as expected. The code does not identify which door or functions that module controls.

At a glance

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

How it works

Door Control Module D exchanges status and control messages with other modules over the vehicle network; the letter D is a network label and does not establish which door it serves. A monitoring module sets U0202 when expected messages from that specific module are missing or invalid for the vehicle’s calibrated period.

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. Record all module codes and freeze-frame details, then check whether U0202 is current and whether other communication codes appeared at the same time.
2. Use a capable scan tool to see whether Door Control Module D responds and whether other modules report it as offline; widespread missing modules point toward a network or gateway issue.
3. Check the vehicle’s wiring information to locate Module D, then inspect its connectors, harness, and grounds for looseness, corrosion, water intrusion, or damage.
4. Check the module’s power and ground circuits under the manufacturer’s specified test conditions, since a missing supply can make the module disappear from the network.
5. If power and ground are sound, test the relevant CAN wiring and network termination against the manufacturer’s specification, and assess gateway routing if other network faults are present.

Common fixes

• Repair a loose, corroded, wet, or damaged Module D connector or harness.
• Restore a failed power feed or ground to Door Control Module D.
• Repair a CAN wiring or termination fault identified by testing.
• Address a gateway routing fault if network evidence points to it.

Can I keep driving?

If only door-related functions are affected and the vehicle drives and steers normally, a short necessary trip may be possible, but expect those functions to remain unavailable. Avoid driving if other modules show faults that affect safe operation, and secure doors and windows before travel.