What it means
This usually means the transmission fluid or transmission is too hot. Red generally signals a serious condition that calls for stopping as soon as it is safe, but colour and exact behaviour vary by manufacturer; follow the owner’s manual.
What the symbol looks like: A thermometer above wavy lines, sometimes shown beside a gear or transmission symbol, is a common transmission-temperature warning; designs vary.
Why it comes on
- Prolonged stop-and-go driving or heavy towing
- Repeated hard acceleration or driving on steep grades
- Low or leaking transmission fluid
- A transmission cooling-system problem
- An internal transmission fault
What to do
- Ease off the accelerator and pull over safely as soon as possible.
- Select Park or neutral and apply the parking brake.
- Follow the owner’s manual about whether to leave the engine running or switch it off; do not open hot fluid-system parts.
- If the warning does not clear as described in the manual, or there is smoke, a burning smell, or abnormal shifting, arrange recovery.
Can I keep driving?
Do not continue driving with an active overheating warning; continued operation can cause serious transmission damage. Avoid towing or strenuous driving until the cause is resolved.
Symbols and colours differ between makes and models. Your owner’s manual shows the exact lights of your car.