What it means
A module reports a software version mismatch with glow plug control module 2 — typically after replacing one of the modules without programming the new unit to match the rest of the network.
At a glance
- Usually lights the warning light of the system that lost communication
- Affects emissions; the car can fail an emissions test
How it works
Glow plug control module 2 manages a designated group or stage of glow plugs that warm a diesel engine for starting and cold operation. U030B sets when another module detects that module 2's software or configuration is incompatible with the expected version, often after replacement or incorrect programming.
Common causes
Most likely first.
- Module replaced without programming
- Wrong part number for the vehicle
- Gateway module routing CAN messages incorrectly
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
- Save all codes and freeze-frame data, distinguishing glow plug module 2 faults from faults reported for other glow plug modules.
- Check for a recent replacement or software update and verify module 2's part and software identification against the manufacturer's application information.
- Review scan-tool data for module 2 communication, commanded operation, and any related glow plug or cold-start faults.
- Inspect module 2's power, ground, connectors, and CAN wiring for damage, corrosion, or loose terminals.
- Check the gateway and CAN network using the manufacturer's diagnostic procedure before condemning module 2.
- If wiring and network checks pass, program the correct software and configuration for glow plug module 2, then verify communication and cold-start operation.
Common fixes
- Repair poor power, ground, connector, or CAN wiring at glow plug control module 2.
- Correct module 2's configuration if it does not match the vehicle.
- Reprogram module 2 with compatible software.
- Replace an incorrect or faulty module 2 and program the replacement.
Can I keep driving?
If the engine starts and runs normally, a short trip is generally possible, but cold starts may become difficult or smoky if glow plug operation is affected. Avoid repeated prolonged cranking, which can drain the battery and strain the starter.
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.