AutoCodes – MINI – P1159 MINI

P1159 MINI Code - Fuel Trim Adaptation Additive High Bank 1

Quick Answer

Short term fuel trim (STFT) is a value that indicates how the Engine Control Module (ECM) is adapting the factory programmed fuel map. Common causes include Air leaks, Faulty Mass Air Flow (MAF) Sensor, Faulty Oxygen Sensor Bank 1. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P1159 MINI indicates Fuel Trim Adaptation Additive High Bank 1.
Common causes: Common causes include Air leaks, Faulty Mass Air Flow (MAF) Sensor, Faulty Oxygen Sensor Bank 1.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 1,665

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 23, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1159 MINI Description

Short term fuel trim (STFT) is a value that indicates how the Engine Control Module (ECM) is adapting the factory programmed fuel map. The fuel map is a lookup table that is referred to by the controller. This is used to govern the correct amount of fuel to inject. This amount depends on the speed and load conditions monitored on the vehicle. The (STFT) Value alters depending on which fuel map load cell the engine is operating during speed and load conditions.
The oxygen sensor is a key part of the fuel trim calculation. If the Oxygen sensor indicates a lean mixture, the (STFT) will be increased above the typical Value. If the Oxygen Sensor indicates a rich mixture the (STFT) will be reduced below the typical Value. In normal operation, the fuel trim values will cycle between a maximum of 10 and -10%. (STFT) which exceed this Value should be investigated.

OBDII Code P1159 MINI - Fuel Trim Adaptation Additive High Bank 1 - AutoCodes.com — P1159 MINI Code - Fuel Trim Adaptation Additive High Bank 1

What does this mean?

What are the Possible Causes of the DTC P1159 MINI?

Air leaks
Faulty Mass Air Flow (MAF) Sensor
Faulty Oxygen Sensor Bank 1
Low Fuel Pressure
Faulty Spark Plugs
Faulty Fuel Injectors

How to Fix the DTC P1159 MINI?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1159 MINI code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P1159 MINI code?

Need more information on how to fix the P1159 MINI code? Get Access to Factory Service Manuals

Need Help with the Code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1159 MINI Code

1. What does the OBDII code P1159 mean for a MINI?

P1159 indicates "Fuel Trim Adaptation Additive High Bank 1," meaning the engine control module has detected a fuel mixture imbalance, usually running too rich or too lean on Bank 1.

2. What are the common symptoms of P1159 in a MINI?

Symptoms may include poor fuel economy, rough idling, hesitation during acceleration, and the check engine light being illuminated.

3. What causes the P1159 code in a MINI?

Potential causes include a vacuum leak, dirty or failing mass air flow (MAF) sensor, clogged fuel injectors, or a malfunctioning oxygen sensor.

4. How can a vacuum leak cause the P1159 code?

A vacuum leak can allow unmetered air into the engine, disrupting the air-fuel mixture and triggering the fuel trim adaptation error.

5. Can a bad oxygen sensor lead to the P1159 code?

Yes, a faulty oxygen sensor can provide inaccurate data about the air-fuel mixture, causing the ECU to adjust fuel trim incorrectly.

6. How is the P1159 code diagnosed?

A mechanic will typically inspect for vacuum leaks, test the mass air flow sensor, check fuel injectors, and analyze oxygen sensor readings using a diagnostic scanner.

7. Can the P1159 code affect engine performance?

Yes, the code can result in reduced power, inefficient fuel consumption, and potential damage to the catalytic converter if not addressed.

8. What repairs are commonly needed to fix the P1159 code?

Repairs may include fixing vacuum leaks, cleaning or replacing the MAF sensor, replacing faulty oxygen sensors, or servicing fuel injectors.

9. Is it safe to drive with the P1159 code on a MINI?

While the car may still run, driving with this code can lead to further engine damage and decreased performance, so it’s best to address the issue promptly.

10. Can the P1159 code be cleared without repairs?

Clearing the code without addressing the underlying issue may temporarily turn off the check engine light, but the code will likely return until the root cause is fixed.