What it means
A control module is not receiving expected messages from the Compass Module. Compass or heading information may be unavailable; the code alone does not identify why communication was lost.
How it works
The compass module calculates or supplies heading information and sends it over the vehicle network. A receiving control module sets U0161 when it does not receive the expected messages from that compass module within the required time; the code does not show whether the module, its power, the CAN connection, or message routing failed.
Common causes
Most likely first.
- Compass module unpowered
- CAN wiring to compass module broken
- Gateway module routing CAN messages incorrectly
Symptoms
- Compass or heading information may be unavailable
- Other communication codes
How to diagnose it
- Scan all modules for communication codes and review freeze-frame or event data to see whether other modules lost contact at the same time.
- Check whether the compass or heading display is unavailable and whether the compass module appears in a full-module scan.
- Inspect the compass module's power, ground, CAN wiring, and connectors for loose contacts, corrosion, damage, or water entry.
- Check the module's power and ground under load against the manufacturer's specification, since a supply fault can make it disappear from the network.
- Test the CAN connection at the compass module and check gateway routing using the manufacturer's wiring information and diagnostic procedures.
Common fixes
- Restore a loose or corroded compass-module connector.
- Repair damaged power, ground, or CAN wiring to the compass module.
- Correct a failed power or ground connection at the module.
- Repair gateway configuration or routing if network tests point to it.
- Replace the compass module only after its supplies and network connections test correctly.
Can I keep driving?
A missing compass reading usually does not affect basic driving, but other communication codes may indicate a broader network fault. If several vehicle functions or warning messages appear, limit driving and have the network fault diagnosed.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.