These instructions apply to the Cadillac CT6 (2016-2020).
For other models, please choose your vehicle here.
After an oil change on your Cadillac CT6 (2016–2020), the Oil Life service indicator needs resetting so the countdown starts again. You can do it yourself — there are two methods. Both are done from the driver’s seat in under a minute, with no tool to connect, so once the fresh oil is in you can restart the monitor straight away.
What the Oil Life System Means
The CT6 uses an Oil Life System, shown as an oil-life percentage and a ‘Change Engine Oil Soon’ or service message. This is a maintenance reminder, not a fault. Rather than counting down on a fixed mileage alone, the Oil Life System estimates how much useful life is left in the oil from how the car has actually been driven — things like engine revolutions, operating temperature and driving conditions — and displays that as a percentage. When it drops to a low value, the car asks you to change the oil.
Because the system tracks remaining oil life, it must be reset only after the oil has actually been changed. If you reset it without changing the oil, the monitor will read 100% while the oil is really worn, and you’ll lose the benefit of the system. If you skip the reset after a change, it will keep showing a low value and prompt you again too soon. For the recommended service intervals, follow the maintenance schedule in your owner’s handbook.
Before You Start
- Only reset after the oil has actually been changed.
- Park safely on level ground with the vehicle stationary.
- Ignition on, engine off for the reset — you do not need the engine running.
- No tools required — everything is done with the on-board controls.
Method 1 — SEL/RESET Button
- With the brake pedal released, press the ‘SEL/RESET’ button until the ‘OIL LIFE’ message appears.
- Press and hold ‘SEL/RESET’ until ‘100% OIL LIFE’ is displayed.
- Press the start/stop button to switch the ignition off.
Method 2 — Accelerator Pedal
- With the brake released, press the start/stop button (without the brake) to switch the ignition on.
- Press and release the accelerator pedal 3 times.
- ‘100% OIL LIFE’ appears — switch the ignition off.
Both methods do the same job; use whichever is easier for you. The confirmation in each case is the display reading ‘100% OIL LIFE’ — if you don’t see that, the reset hasn’t taken and you should try again.
If the Reset Doesn’t Take
- Don’t press the brake when switching on for the pedal method.
- Wait for ‘100% OIL LIFE’ to confirm.
- Press the accelerator fully and evenly for the pedal method — three clear presses within a few seconds.
- Switch off and retry if nothing changes; cycle the ignition and run the method again from the start.
- A service light that won’t clear can store a code — look it up on autodtcs.com.
What to Expect After Resetting
Once the display shows ‘100% OIL LIFE’ and you switch off, the oil-life percentage is restored to full and the change-oil message is cleared. At the next start the reminder should be gone, and the percentage will begin to fall again gradually as you drive. If the message returns straight away, the reset didn’t confirm — repeat one of the two methods and watch for the 100% reading.
How Often to Reset It
Reset the Oil Life System every time you change the oil — once per oil service, immediately after the work. Because the system is condition-based, the interval between changes will vary with how the car is driven rather than being a single fixed figure. Follow the guidance in your owner’s handbook, and change the oil whenever the monitor calls for it or at the maximum time limit, whichever comes first.
Frequently Asked Questions
How do I reset the oil life light on a Cadillac CT6?
Use SEL/RESET to OIL LIFE then hold until 100%, or ignition on (no brake) and press the accelerator 3 times.
Do I need a tool?
No — both methods are done from the driver’s seat.
How do I switch on without starting?
Press the start/stop button without pressing the brake pedal.
Should I reset before or after the oil change?
After — the indicator monitors oil life, so resetting it before changing the oil defeats the purpose.
What does the oil-life percentage actually measure?
It is an estimate of remaining oil life based on how the car has been driven, not a simple mileage countdown, which is why the interval varies.
Which method should I use?
Either works. The SEL/RESET button method uses the driver display; the accelerator method is a handy alternative if you prefer it — both end with ‘100% OIL LIFE’.
If a service-related warning stays on, decode the code on autodtcs.com.
Independent guide — not affiliated with Cadillac. Always follow your official service manual and safety precautions. Read our full disclaimer.