U0230 — Lost Communication With Rear Gate Module

OBD2 code U0230 flags a problem with the vehicle network (CAN bus) communication (lost communication with rear gate module). Short, gentle driving to a shop is usually possible. Common culprits: corroded connectors, especially in wet areas, aftermarket equipment interfering with the bus, damaged CAN bus wiring or short to power/ground.

vehicle network

Is it safe to drive?

Drive with caution Depends on what is affected. A single dead convenience module is fine to drive with; loss of communication with engine, braking or steering modules is not. If multiple critical systems drop out, do not drive.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm U0230 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many U0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the vehicle network (CAN bus) communication for damage, corrosion, chafing or poor contact.
Subsystem check Measure resistance between CAN-High and CAN-Low at the OBD port with power off — about 60 Ω is healthy.
Subsystem check Scan all modules: the one that does not respond is either the culprit or downstream of the break.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm U0230 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for U0230 (parts and labor, USD, independent shop rates): Repair CAN wiring or connectors: $100–$400; Replace the faulty control module: $300–$1,500; Remove interfering aftermarket device: $0–$150. Overall, fixing U0230 usually costs between $0 and $1,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

How do I diagnose U0230 myself?

Start with a scan: confirm U0230, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the vehicle network (CAN bus) communication, and verify the suspect component against live data before buying parts.

What is the most common cause of U0230?

The most common causes are: corroded connectors, especially in wet areas, aftermarket equipment interfering with the bus, damaged CAN bus wiring or short to power/ground.

What does OBD2 code U0230 mean?

Will U0230 clear itself?

Sometimes U0230 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

Is it safe to drive with U0230?

Depends on what is affected. A single dead convenience module is fine to drive with; loss of communication with engine, braking or steering modules is not. If multiple critical systems drop out, do not drive.

What does U0230 mean?

Seeing U0230 on your scanner? The control unit has caught the vehicle network (CAN bus) communication operating outside its calibrated window. The formal description is “Lost Communication With Rear Gate Module”, and the code is grouped under vehicle network faults.

To set U0230, the control module compares live readings of the vehicle network (CAN bus) communication against calibrated limits, usually over several drive cycles. Alongside the code it stores a freeze frame — a snapshot of rpm, load, coolant temperature and vehicle speed at the moment of failure. Reading that snapshot first saves diagnostic time.

What causes U0230?

water ingress in harness junctions
a faulty module pulling the bus down
aftermarket equipment interfering with the bus
corroded connectors, especially in wet areas

Common symptoms of U0230

intermittent loss of functions (gauges, windows, steering assist)
random, hard-to-reproduce electrical glitches
multiple warning lights on at once
no-start or intermittent starting in some cases
modules intermittently not communicating with the scanner

How to diagnose U0230

Connect an OBD2 scanner, confirm U0230 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many U0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Visually inspect the wiring harness and connectors related to the vehicle network (CAN bus) communication for damage, corrosion, chafing or poor contact.
Measure resistance between CAN-High and CAN-Low at the OBD port with power off — about 60 Ω is healthy.
Scan all modules: the one that does not respond is either the culprit or downstream of the break.
Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm U0230 does not return.

How to fix U0230

Start with the cheapest and most common causes before replacing expensive parts:

Repair CAN wiring or connectors — $100–$400
Replace the faulty control module — $300–$1,500
Remove interfering aftermarket device — $0–$150

How much does it cost to fix U0230?

Repair cost depends on which component actually failed. Typical scenarios for U0230 (parts and labor, USD, independent shop rates):

Repair CAN wiring or connectors: $100–$400
Replace the faulty control module: $300–$1,500
Remove interfering aftermarket device: $0–$150

Overall, fixing U0230 usually costs between $0 and $1,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.