Code 89 on Vauxhall Mokka (Causes and How to Fix)

ByChalobah Leonard General Car Tips

If you’ve just noticed ‘Code 89’ on your Vauxhall Mokka’s dashboard, you may be wondering what it means. If that sounds like you, keep reading!

‘Code 89’ on a Vauxhall Mokka is often triggered by a variety of issues, such as a faulty engine coolant temperature sensor, wiring issues, or ECU malfunction. You’ll need to get your vehicle checked, then fix the main issues that triggered the error code.

In this guide, we’ll dive deeper into the causes of ‘Code 89’, how to diagnose the problem, and the steps you can take to fix it.

What Does Warning Code 89 Mean On a Vauxhall Mokka?

Code 89 Vauxhall Mokka

Code 89 on a Vauxhall Mokka typically indicates a fault in the engine’s sensor circuit, specifically related to the catalytic converters. The code may also be triggered by a faulty thermostat or a problem with the engine’s exhaust system. 

The check engine light may illuminate when this code appears. You should take the vehicle to a professional mechanic for diagnosis and repair. The cost of repair will depend on the specific issue and the level of damage. 

Possible Causes of Code 89 on Vauxhall Mokka

If you have seen the check engine light on your dashboard with ‘Code 89’, it indicates that there is an issue with the engine. Here are some possible causes of this error code:

Engine Coolant Temperature Sensor Malfunction

The engine coolant temperature sensor is responsible for monitoring the temperature of the engine and sending that information to the engine control unit (ECU). A malfunctioning sensor may cause the ECU to think that the engine is overheating, triggering the Code 89 warning.

Wiring Issues

If the wiring connections to the engine coolant temperature sensor are loose or damaged, it can also trigger Code 89. This is because the ECU is unable to receive accurate temperature readings from the sensor due to the wiring issues.

ECU Malfunction

In some rare cases, a malfunctioning ECU can also be responsible for the Code 89 warning. If the ECU is not receiving accurate temperature readings from the engine coolant temperature sensor, it may display this error code.

Low Coolant Level

A low coolant level can also trigger the Code 89 warning. This is because the engine coolant helps to regulate the temperature of the engine, and a low level can cause the engine to overheat.

Failed Thermostat

A failed thermostat can also cause the engine to overheat and trigger the Code 89 warning. The thermostat regulates the flow of coolant through the engine and if it fails, it can cause the engine to overheat.

Related Post: How to Reset Code 82 Vauxhall Mokka.

How to Diagnose Code 89 on Vauxhall Mokka

Here are some steps to diagnose and potentially fix the issue:

  • Use an OBD2 Scanner: An OBD2 scanner can help you read and clear the trouble codes that your vehicle’s computer is generating. This will give you a better idea of what is causing Code 89 to appear.
  • Check the Coolant Level: If your coolant level is low, it could be causing the engine to overheat and generate a Code 89. Check the coolant level and add more if necessary.
  • Inspect Wiring and Connections: A loose or damaged wire or connection in the cooling system can also trigger a Code 89. Inspect all connections and wiring to ensure they are secure and free from damage.
  • Check Thermostat Function: A faulty thermostat can also cause issues with the cooling system and trigger a Code 89. Check the thermostat to ensure it is functioning properly.
  • Perform a Compression Test: A compression test can help you determine if there are any issues with the engine’s internal components, such as the head gasket or piston rings. If the compression test reveals any issues, further repairs may be necessary.

How to Fix Code 89 on Vauxhall Mokka

Here are some possible fixes for Code 89:

1. Replace the Engine Coolant Temperature Sensor

The engine coolant temperature sensor monitors the temperature of the coolant and send signals to the engine control unit (ECU) to adjust fuel injection and ignition timing. If the sensor is faulty or damaged, it can trigger Code 89. A mechanic can replace the sensor to resolve the issue.

2. Repair or Replace Faulty Wiring and Connections

Sometimes Code 89 can be caused by faulty wiring or connections between the engine coolant temperature sensor and the ECU. A mechanic can inspect the wiring and connections to identify and fix any issues.

3. Replace the ECU

If the engine coolant temperature sensor and wiring are not the issue, it may be a problem with the ECU itself. In this case, a mechanic may need to replace the ECU to fix the problem.

4. Add Coolant to the System

Low coolant level can also trigger Code 89. Check the coolant level and add more if needed. If the coolant level is consistently low, there may be a leak in the system that needs to be repaired.

5. Replace the Thermostat

A bad thermostat can cause the engine to overheat, which can trigger Code 89. A mechanic can inspect and replace the thermostat if needed.

Tips to Prevent Code 89 on Vauxhall Mokka

Here are some tips to prevent Code 89 on your Vauxhall Mokka:

Regular Maintenance and Inspections

Regular maintenance and inspections are crucial to prevent Code 89 and other engine-related problems.

Follow the manufacturer’s recommended maintenance schedule, which includes regular oil changes, filter replacements, and coolant level checks. Additionally, have your Mokka inspected by a professional mechanic to detect any issues early on.

Using High-quality Coolant

Using high-quality coolant is essential to prevent Code 89 on your Vauxhall Mokka. Use a coolant that meets the manufacturer’s specifications and replace it regularly.

Low-quality coolant or old coolant can cause corrosion and damage to the engine, leading to code 89.

Properly Maintaining the Engine

Properly maintaining the engine is another essential factor in preventing Code 89. Keep the engine oil at the proper level and replace it regularly.

Additionally, inspect the exhaust system regularly for any leaks or damage that could cause Code 89.

Not Ignoring Warning Signs

If you notice any warning signs, such as the check engine light or unusual engine noise, don’t ignore them.

Ignoring warning signs can lead to more severe problems and more expensive repairs in the long run. Instead, have your Mokka inspected by a professional mechanic as soon as possible.

Related: What is Code 82 on Vauxhall Astra? 

Wrapping Up

The Code 89 warning on a Vauxhall Mokka indicates that there is an issue with the engine or emissions control system. It’s important not to ignore this warning, as it could lead to further damage to your vehicle.

Take your Vauxhall Mokka to a qualified mechanic or an authorized Vauxhall service center for proper diagnoses and repairs. The mechanic can also help you reset the Code 89 warning light after the repairs.