2023-2024 BMW 5 Series, 7 Series, iX Reduced Interior Heating TSB

BMW has issued Service Information Bulletin SIB 64 05 24 to address customer concerns regarding BMW reduced interior heating and limited defroster function in certain 2023-2024 models. This technical service bulletin, dated March 27, 2024, outlines a diagnostic and repair procedure for vehicles experiencing these symptoms in cold temperatures.

Symptoms

Owners of affected vehicles may notice that the "defroster function is limited" and the "interior doesn't heat up quickly enough" when the ambient temperature is between 5°F (-15°C) and 23°F (-5°C). This can lead to discomfort and reduced visibility during cold weather driving.

Cause

The root cause of the BMW reduced interior heating problem is identified as software within the Basic Central Platform (BCP) of the vehicle.

Diagnosis and Repair Procedure Summary

To address the issue, technicians will first determine the vehicle's current integration level (I-level) using BMW's AIR or AWP applications. The repair procedure follows two main paths:

1. Software Update: If the vehicle's current I-level is lower than G070-22-11-540 (for G60/G70 models) or I020-22-11-540 (for i20 models), the vehicle must be programmed using ISTA (version 4.46.1 or higher). The target integration level after programming will be G070-24-03-525 or higher for G60/G70 models, and I020-24-03-525 or higher for i20 models. This software update is the primary correction for the BMW reduced interior heating.

2. Interior Temperature Sensor Replacement: If the vehicle's I-level is already at G070-22-11-540 or higher, and the customer still reports the heating concern, then the interior temperature sensor (part B857) should be replaced. This step is only performed if the software update is not applicable or does not resolve the issue. Technicians will follow Repair Instruction 6411938 for this replacement.

After either procedure, the functionality of the heating system should be checked to ensure the problem is resolved.

Required Parts

If a sensor replacement is necessary, the following parts may be required. These parts are expected to be available mid-April 2024.

• 61 31 5 A8B 534: Interior Temperature Sensor for G60 / G70 models
• 61 31 5 A8B 530: Interior Temperature Sensor for i20 models

Important Notes for Owners

• Sensor Replacement is Secondary: Owners should be aware that the interior temperature sensor should only be replaced if the software update does not resolve the customer's concern. This prevents unnecessary part replacements.
• Battery Charger Requirement: During any programming or coding procedures, a BMW-approved battery charger/power supply (refer to SI B04 23 10) must be connected to maintain stable voltage.
• Warranty Coverage: The BMW software solution for this issue is covered under the terms of the BMW New Vehicle Limited Warranty for Passenger Cars and Light Trucks, or the BMW Certified Pre-Owned Program, where applicable.
• Consequential Repairs: If any control modules fail during the reprogramming process, additional repair procedures may be required and claimed under Repair Code 6411308000, which is associated with a "Passenger compartment temperature sensor (centre vent, footwell air outlet) short circuit" diagnosis.

NHTSA ID: 10252133