U030BNetwork · Invalid data & softwareGeneric (SAE) code

U030B: Software Incompatibility With Glow Plug Control Module 2

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.

Typical labor cost
$65–$250 est.
30 min–2 h at an assumed $125/hr · parts extra · use your rate
Most common fix
Module replaced without programming
DIY difficulty: Moderate · usually a shop job
01 —What it means

What U030B means

U030B is a generic OBD-II network code in the invalid data & software group.

U
Network
0
Generic (SAE)
3
Subsystem group
0B
Specific fault
How to read U030B. We group it under Invalid data & software.
Check engine light
Usually on
Emissions-related
Yes — can fail inspection
Limp mode possible
Not typical
Drive cycle to clear
Not required
Code data: OBDex (CC0)

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02 —Symptoms

Symptoms

What drivers typically notice
  • 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
Code data: OBDex (CC0)
03 —Causes

Common causes

Ranked from most to least likely
  1. 01Module replaced without programmingMost likely
  2. 02Wrong part number for the vehiclePossible
  3. 03Gateway module routing CAN messages incorrectlyLess likely
Code data: OBDex (CC0)
04 —Severity

Can I drive with U030B?

Moderate

Usually yes, for a short time.

The car will often drive normally, but get it diagnosed soon. Left alone it can raise fuel use and emissions and will fail an OBD inspection. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.

Why we rate it moderate

  • Turns on the check engine light
  • Emissions-related: will usually fail an OBD inspection

Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.

Code data: OBDex (CC0)
05 —Diagnosis

How to diagnose U030B

General procedure — follow the service manual for your vehicle
  1. 1

    Confirm the code and save freeze-frame data

    Read the codes with an OBD-II scan tool and note every code, not just U030B. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.

  2. 2

    Fix other faults first

    If other codes are stored, start with power-supply, sensor-circuit and communication codes. They can cause this code as a side effect.

  3. 3

    Check live data

    Watch the related sensor and actuator readings in live data (Glow plug module 2) and compare them with expected values in the service information for your vehicle.

  4. 4

    Test the likely causes in order

    Start with the most likely cause and work down: Module replaced without programming; wrong part number for the vehicle; gateway module routing CAN messages incorrectly. Test before replacing parts.

  5. 5

    Check for recalls and service bulletins

    Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.

  6. 6

    Clear the code and verify the repair

    After the repair, clear the code and drive the car under the conditions in the freeze-frame data to confirm it does not return.

Code data: OBDex (CC0)
06 —Cost

U030B repair cost estimate

Labor only — set your local shop rate
Labor estimate for U030B
$65–$250
30 min–2 h of labor × $125/hr (assumed rate) · parts extra

Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.

DIY difficulty
Moderate
Good DIY job?
Usually a shop job

Needs a scan tool and some experience with testing.

Code data: OBDex (CC0)
07 —Components

Parts and systems involved

  • Glow plug module 2
Code data: OBDex (CC0)
09 —FAQ

U030B FAQ

What does U030B mean?

U030B means “Software Incompatibility With Glow Plug Control Module 2”. 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.

Is U030B serious? Can I keep driving?

We rate U030B as moderate severity. Usually yes, for a short time. The car will often drive normally, but get it diagnosed soon. Left alone it can raise fuel use and emissions and will fail an OBD inspection. If you notice rough running, warning lights flashing, overheating or a burning smell, stop driving.

What causes U030B?

The most common causes, from most to least likely: Module replaced without programming; Wrong part number for the vehicle; Gateway module routing CAN messages incorrectly. Test before replacing parts, because several causes can set the same code.

How much does it cost to fix U030B?

Typical labor is about $65–$250 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.

Can I fix U030B myself?

DIY difficulty is moderate. Most owners leave this to a shop because it needs involved testing or specialist tools. Always confirm the cause before buying parts.

Will U030B clear itself?

If the fault was intermittent, the warning may go off once the computer stops seeing it, but the code stays in memory. Fix the cause; clearing the code alone doesn’t repair anything.

Code data: OBDex (CC0)