BA0008

What BA0008 Means

Code BA0008 points to an implausible signal from the internal coolant temperature sensor inside the Combined Charging Unit (CCU). This sensor monitors the temperature of the charger's components, but in this case the fault isn't a physical sensor failure — it's a software bug in the CCU software.

The fault can be stored in CCU memory together with code BA0023. The cause is unfavorable Combined Charging Unit (CCU) software that falsely sets BA0023 and BA0008 and triggers the malfunction indicator lamp (MIL). The problem affects plug-in hybrids (PHEV) with the CCU_P1 unit (7.4 kW and 11 kW) at I-levels from …24-07-500 to …25-11-5xx.

Affected Components

• Combined Charging Unit (CCU) — the charging control unit.
• CCU internal coolant temperature sensor.
• CCU software (I-level).

Symptoms

• The malfunction indicator lamp (MIL) may come on.
• Faults BA0023 and BA0008 may be stored in CCU memory.
• AC charging keeps working normally, with no related complaints about handling or charging.

Diagnosis and Repair

Step 1. Determine the Current I-Level

Use AIR or Key Reader/Aftersales Workplace (AWP) to determine the vehicle's current I-level.

Step 2. Check the Software Version

• If the I-level is below …26-03-500: do not continue the repair. An ISTA version with the software fix is expected in March 2026.
• Clear fault codes BA0023 and BA0008.

Step 3. What to Do Until I-Level 26-03-500 Arrives

• Until I-level 26-03-500 is released, the problem can recur multiple times.
• If AC charging works normally and there are no charging complaints, replacing the CCU won't fix the problem and isn't approved.
• Tell the customer there's no operational problem with the vehicle and the software update is expected in March 2026; return the vehicle to the customer.

Important Notes

• CCU replacement isn't approved because the problem is software-related.
• You'll need to wait for I-level 26-03-500.