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U0215 — Lost Communication Door Switch

Generic OBD-II · all makesNetwork / communication

U0215 indicates that the vehicle's lost communication with the door switch circuit, typically the door‑lock module. The code is set when the expected CAN/LIN message from the door switch is not received within the timeout period.

Symptoms

What causes it — most likely first

1. Failed door switch (door ajar sensor)

The mechanical switch inside the door latch assembly can wear out or stick, preventing it from sending the correct signal to the body control module.

2. Damaged wiring or corroded connector in the door switch circuit

Harness chafing, pinched wires, or moisture‑induced corrosion can interrupt the signal between the switch and the control module.

3. Faulty door control module or body control module (BCM) input circuit

If the module’s internal driver for the door switch input fails, it will not recognize the switch state even when the switch and wiring are good.

4. Loose or poor ground at the door switch or module

An inadequate ground reference can cause intermittent communication errors that trigger the code.

5. Software glitch or outdated module calibration

Rarely, a corrupted module firmware can misinterpret valid switch signals as lost communication.

6. PCM/ECM communication failure (unlikely)

The powertrain control module is only involved if it shares the same network and its CAN transceiver is defective; this is a very uncommon cause for U0215.

How it's diagnosed

  1. Scan for any additional DTCs, especially those related to the BCM or door modules, to identify concurrent network issues.
  2. Visually inspect the door latch assembly and wiring harness for signs of damage, corrosion, or loose connectors.
  3. Test the door switch for proper operation using a multimeter or scan tool live data to verify it changes state when the door is opened/closed.
  4. Check continuity and resistance of the wiring between the switch and the BCM/door module, repairing any open or shorted circuits.
  5. Verify ground integrity at the door switch and at the module side; clean or re‑torque ground points as needed.
  6. If switch and wiring are good, monitor module input signals with a scan tool; replace the door control module or BCM only if its input driver is faulty.
  7. Consider re‑flashing or updating module software if all hardware checks pass and the code persists.

Code facts & related codes

SystemNetwork / communication
StandardizationSAE generic — identical on every make
Related codesU0210 — Lost Communication Seat Control ModuleU0211 — Lost Communication Seat Control ModuleU0212 — Lost Communication Steering Column ConU0213 — Lost Communication Mirror Control ModuU0214 — Lost Communication Remote Function ActU0216 — Lost Communication Door Switch B

Frequently asked

Is replacing the PCM/ECM a common fix for U0215?

No. The PCM is rarely at fault for this code; the issue is almost always in the door switch, its wiring, or the door/body control module. Replacing the PCM without first checking those components is unlikely to resolve the problem and is not recommended.

Can a blown fuse cause U0215?

A blown fuse that powers the door switch or its control module can prevent communication and trigger the code. Checking the relevant fuses is an early diagnostic step.

How often does moisture cause this code?

Moisture ingress leading to connector corrosion or harness shorts is a frequent cause, especially in vehicles exposed to wet climates or frequent washing.