Troubleshooting Guide for BMW & MINI Heater Issues

Troubleshooting Guide for BMW & MINI Heater Issues

Troubleshooting Guide for BMW & MINI Heater Issues

If you're experiencing heating issues in your BMW or MINI, it may be due to either broken stops in the heater box (the most common issue) or a broken shaft. Addressing these problems promptly is essential for maintaining comfort and ensuring efficient vehicle operation. Below is a troubleshooting guide to help you identify and resolve these heating issues.

1. Identifying the Problem

Common Symptom:

• Inability to regulate the temperature on one side of the car — commonly stuck in full cold.

Typical Fault Codes:

• 801189 - Engine mixed air right: Initialization fault

• 801126 - Engine mixed air right: Initialization fault

2. Addressing Broken Stops or a Broken Shaft in the Heater Box

A. Broken Stops (Most Common Issue)

Symptom: Inability to control temperature properly on one side.

Action: A broken stop within the heater box causes the actuator to go into fail mode and stop operating.

Solution: The “Heater-Fix Kit” includes reinforced stops that are added between the actuator and the heater box to restore proper function.

B. Broken Shaft (Less Common Issue)

Symptom: Complete failure of temperature control; the shaft is able to rotate more than 70 degrees and is disconnected from the mixing flap.

Action: A broken shaft within the heater box prevents the mixing flap from functioning correctly.

Solution: The "Broken Shaft Complete Repair Kit" includes a drill guide, 29mm hole saw, replacement shaft, and stop insert to facilitate the repair.

 

 

Installation Process for Broken Stops (Heater-Fix Kit)

  1. Remove the Kick Panel:

• Detach the kick panel to access the actuator.

  1. Uninstall the Actuator:

• Unplug the Actuator: Ensure the vehicle is turned off before disconnecting the actuator's electrical connector.

• Remove Mounting Screws: Unscrew the two screws securing the actuator in place.

  1. Inspect the Shaft:

• Manual Rotation: Check if the shaft can be moved by hand into both cold and hot positions.

• Set Desired Position: Leave the shaft in a position where the temperature is set as desired.

  1. Reinstall the Actuator:

• Without Electrical Connection: Reattach the actuator without connecting the plug to maintain the desired temperature temporarily.

  1. Install the Heater Fix Kit:

• Remove Actuator Again: Once the kit is received, remove the actuator.

• Install Reinforced Stops: Fit the stops as per the kit's instructions, ensuring the shaft can rotate and hit the stops in both hot and cold settings.

  1. Final Assembly:

• Reattach Actuator with Extended Screws: Use the longer screws provided in the kit to secure the actuator.

• Reconnect Electrical Plug: Ensure the actuator's electrical connector is properly connected.

• Reinstall Kick Panel: Put the kick panel back into place.

  1. Clear Fault Codes:

• Use a diagnostic tool to clear any fault codes in the controller.

Outcome: You should now have restored control over the vehicle's temperature settings.

 

 

Installation Process for Broken Shaft (Broken Shaft Complete Repair Kit)

  1. Access the Actuator:

• Remove Trim Panels: Detach the necessary trim panels to expose the actuator.

• Disconnect Electrical Connector: Ensure the vehicle is turned off before unplugging the actuator's electrical connector.

  1. Remove the Actuator:

• Unscrew Mounting Screws: Remove the two screws holding the actuator in place.

  1. Verify Shaft Condition:

• Check for Breakage: Confirm that the shaft is broken by noting if it rotates more than 70 degrees.

  1. Prepare for Drilling:

• Install Drill Guide: Attach the drill guide from the kit to the designated position on the heater box.

• Drill Access Hole: Use a 29mm hole saw (without the center drill bit) to create an access hole through the guide.

  1. Clean the Area:

• Remove Drill Guide: Take off the drill guide after drilling.

• Vacuum Debris: Clean the interior of the heater unit by removing any debris resulting from drilling.

  1. Checking the position of the mixing flap

• The Mixing flap can be rotated into a wrong position – You should be able to see the interconnection rod where it is connected to the mixing flap.

• The connection needs to be on the forward / upper part of the mixing flap. If not in correct position rotate counterclockwise to correct. See pictures

  1. Install Replacement Parts:

• Apply Bonding Material (Optional): For added stability, apply sealant or glue to the flap/shaft assembly.

• Insert Replacement Shaft: Push the new shaft into place until it clicks, ensuring it engages properly with the mixing flap.

• Verify Movement: Rotate the shaft manually to ensure the mixing flap moves smoothly.

• Install Stop Insert: Place the stop insert, ensuring the shaft is correctly aligned and positioned as per the provided instructions.

  1. Reassemble Components:

• Reinstall Actuator: Attach the actuator back into position using the original screws.

• Reconnect Electrical Connector: Plug the actuator's electrical connector back in.

• Reattach Trim Panels: Secure all previously removed trim panels.

  1. Clear Fault Codes:

• Use a diagnostic tool to clear any existing fault codes in the vehicle's controller.

Outcome: The heater's functionality should now be restored, allowing proper temperature regulation.

3. Enhanced Heater Fix Kit

Our Heater Fix Kit includes all the necessary parts to resolve heating issues in BMW and MINI vehicles without the need to replace the entire heater unit.

We've enhanced the kit by including an additional shaft, making it compatible for use on both the left and right sides.

Each shaft is marked with an "R" (Right) or "L" (Left) to indicate the correct side for installation.

 

The kit for the broken shaft is currently only available for the RH side (LH side kit is planned)

4. Manufacturer-Recognized Issue

BMW/MINI has acknowledged this issue and released troubleshooting guides to their dealers.

Relevant service bulletins include:

MINI SI M64 02 21 Technical Service Bulletin

• Models affected:

• 2017 Clubman

• 2014-2021 Cooper

• 2014-2017 Cooper S

• 2019-2021 Cooper S

• 2021 Cooper SE

• 2018 John Cooper Works

• 2021 John Cooper Works

 

BMW Technical Service Bulletins (TSBs) BMW TSB SI B64 06 21 

• Models affected:

• 2020-2021 228i Gran Coupe xDrive

• 2020-2021 i3 and i3 Range Extender

• 2020-2021 i3s and i3s Range Extender

• 2020-2021 M235i Gran Coupe xDrive

• 2020-2021 X1 sDrive28i and xDrive28i

• 2020-2021 X2 sDrive28i, xDrive28i, and M35i

 

The official fix from BMW/MINI involves replacing the entire heater box, which requires removing the dashboard and can cost over £2000, according to online forums.

Alternative Solution: Our Heater Fix Kit offers a cost-effective repair solution without the need for a full heater box replacement.

This is the original produced kit – there exist other cheaper kits some of them are not using the correct screws or are fabricated in cheaper materials – This kit has been sold more than 200 times and have no reported problems.

 

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