U0333: Software Incompatibility With Gear Shift Control Module B
What to do
Use the parking brake firmly every time you stop, and do not rely on the gear display. Everything at U0304 applies here.
Nothing is broken. Two of your car's computers are running software that does not belong together, and one of them is involved in reading which gear you have asked for.
There is a useful check worth doing before the car goes anywhere. If your car has two ways of changing gear — a lever and paddles, for instance — try both. If one works and the other does not, say so: it tells the garage immediately which half is on the wrong software, and that is much more useful than "it will not select a gear".
The safety point does not change. The car may refuse to come out of park, refuse to go into park, or show a gear it is not actually in. If the car rolls at all when you take your foot off the brake, it is not in park regardless of what the display says — so use the parking brake and avoid slopes.
Mention any module replaced, especially a second-hand one, and any gearbox work. What each lever position means is defined in software, and it changes quietly between model years while the plug and part number stay identical.
What this code means
A second gear shift control module is running software that does not belong with its partners'. Everything at U0304 applies unchanged, including the instruction that follows from it: apply the parking brake deliberately every time, and do not trust the gear display.
What a second selector module means is the useful addition.
Some vehicles split the job: a module in the selector itself reading the lever or rotary control, and a second in the transmission or the console interpreting it and arbitrating with the gearbox. Others genuinely have two controls — a lever and steering wheel paddles, or a console selector and a secondary control for a specialist body — and each has its module.
Where two controls exist, a mismatch produces a disagreement worth recognising: the two ways of selecting a gear no longer behave the same. Paddles that work while the lever does not, or a manual gate that behaves differently from the paddles, is that — and it is much more informative than a general "it will not select", because it tells you which half of the pair is on the wrong software.
So try both controls before the vehicle goes anywhere, and report the difference.
And the safety framing from U0304 does not soften for a secondary control. The vehicle may refuse to leave park, refuse to select park, or display a gear it is not in — and the last is the one a driver acts on. If the vehicle rolls when the brake pedal is released, it is not in park whatever the dashboard says.
Likely causes
Start here
- Second hand module locked to another vehicle · specialist
- Incorrect module configuration after replacement · specialist
- Software updated on one module only · specialist
Less common
- Module not coded to the vehicle · specialist
- Interrupted module programming · specialist
- Software calibration out of date · specialist
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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