Limp mode: why your car suddenly loses power

Limp mode limits power, RPM, or gears to protect the engine or transmission when the control module detects a major fault. The car keeps moving, but with much less response.

What to do if it happens while driving

1. Signal and move out of the fast lanes when it is safe.
2. Check the oil and temperature warnings. If any is red, stop and turn off the engine.
3. If there are no serious warnings, drive gently to a safe place or a repair shop.
4. Read the codes before clearing them or repeatedly turning the car off and on.

Common causes

• Low turbo pressure (P0299) or overboost (P0234).
• Throttle or accelerator pedal faults, such as P2135.
• Low fuel pressure, such as P0087.
• Diesel particulate filter problems, such as P2463.
• Automatic transmission faults, such as P0700.

Does turning the car off clear it?

Sometimes it goes away after restarting, if the fault was a one-time event. If it comes back, it needs to be diagnosed: continuing to drive this way can make the damage worse.