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U0236 — Lost Communication Column Lock Module

Generic OBD-II · all makesNetwork / communication

U0236 indicates the powertrain control module (PCM) has lost serial-data communication with the column-lock module. This usually means the module is not responding on the vehicle network, often due to power, ground, or internal module failure.

Symptoms

What causes it — most likely first

1. Faulty column-lock module

Internal electronics failure is the most common cause. Water intrusion, vibration, or age-related component wear can damage the module.

2. Wiring or connector damage

Open or shorted circuits between the column-lock module and the network bus, or corroded/loose connectors at the module or splice points.

3. Loss of power or ground to the module

Blown fuse, faulty relay, or broken power/ground wire preventing the module from powering up and communicating.

4. Network bus communication issue

Open, short, or high resistance in the CAN or LIN bus wiring shared by multiple modules, disrupting communication.

5. Aftermarket or incorrect module installed

A replacement module that is not properly programmed or calibrated for the vehicle may fail to communicate.

6. PCM/ECM failure (rare)

Only consider if all other causes are ruled out. PCM failure is extremely unlikely to cause only a single-module communication loss.

How it's diagnosed

  1. Verify the code is current and not historic using a scan tool with network-monitoring capability.
  2. Inspect the column-lock module and its connectors for physical damage, corrosion, or loose pins. Check for proper power and ground at the module.
  3. Test the CAN or LIN bus wiring for opens, shorts, or high resistance between the column-lock module and the network. Check termination resistors if applicable.
  4. Attempt to communicate with the column-lock module using a bidirectional scan tool. If no response, check for proper voltage and ground at the module.
  5. If the module responds but communication is intermittent, monitor network traffic while wiggling connectors and wiring harnesses to check for intermittent faults.
  6. If all wiring and power checks pass, replace the column-lock module and ensure proper programming or calibration is performed.

Code facts & related codes

SystemNetwork / communication
StandardizationSAE generic — identical on every make

Frequently asked

Can I drive with U0236 set?

Driving is not recommended. The steering column may remain locked, creating a sudden loss of control. If the vehicle starts, the column lock may engage unexpectedly while driving.

Is the PCM/ECM usually the cause of U0236?

No. The PCM is rarely the cause. U0236 almost always indicates a problem with the column-lock module itself, its wiring, or power supply. Replacing the PCM should only be considered after all other causes are ruled out.

Why does the dealer say I need a new column-lock module?

Dealers often replace the module because it is the most common failure point. However, the issue could also be wiring, connectors, or power/ground problems. Proper diagnosis should confirm the root cause before replacement.

Can I reset the code to clear it?

Clearing the code without repairs may temporarily restore function, but the underlying issue will likely return. The code will reset once the communication fault reoccurs.