What is the IMIB HV?
IMIB HV (Integrated Measurement Interface Box – High Voltage) is BMW’s official diagnostic tool for working with high-voltage systems — the modern successor to the EoS tester. If you’re servicing BMW EVs or plug-in hybrids, this is a must-have device to perform battery diagnostics, unlock crash-protected HV systems, and reassign battery controllers after repair or replacement.
It integrates directly with BMW’s factory diagnostic software ISTA (Integrated Service Technical Application), allowing safe, guided procedures for HV battery inspections and resets after a crash.
What is IMIB HV used for?
In post-accident BMW vehicles, the high-voltage system enters a lockdown. The IMIB HV is essential to:
- Diagnose and test the HV battery,
- Clear crash data stored in the BMS,
- Perform insulation resistance tests,
- Simulate resting bus for safe wake-up procedures,
- Safely re-enable the system via ISTA.
This process is part of BMW’s internal EoS procedure (End-of-Service test) — a mandatory step before a crashed HV battery can be reused or replaced.
Key Functions:
- Final test after HV battery repair
- Full safety test on stored or damaged batteries
- Safety clearance before reuse or disposal
- Resting bus simulation for safe activation
- Dielectric (insulation) strength test
- Pre-charge safety logic test
- Enclosure leak check
- Zero-voltage validation
Error codes that require IMIB HV:
These DTCs (Diagnostic Trouble Codes) signal that the HV battery has entered protection mode:
- 0x21F2A8 – Pyrotechnic disconnect fault (safety terminal not engaged)
- 0x21F37E – Crash signal detected by ACSM (Airbag module)
- 0x21F43C – HV battery voltage too low for system wake-up
Without clearing these via ISTA with IMIB HV, the battery cannot be reused or reassigned.
Connection Overview:
Laptop or ISID Next setup:
- IMIB HV connects to HV battery directly
- ISTA software runs the test procedure
- IMIB MA software (middleware) runs in background
- USB cable connects IMIB HV to the laptop or ISID
Example setup:
- Laptop or BMW ISID Next
- ISTA + IMIB MA installed
- USB cable connection to IMIB HV
- Connected to HV battery module in vehicle
Device Variants:
Two official hardware versions are in circulation:
- 81315A78C5 (Year: 2022)
- 81315A94550 (Year: 2023)
Need real-life photos, connector pinouts, or guided recovery steps?
We’ve done it on the bench at EV Clinic.
Contact us.
INCLUDED:
1x IMIB HV + CABLE AND ADAPTER KIT INCL. TRANSPORT CASE GEN5 BEV TYPE1
1x CABLE AND ADAPTER KIT INCL. TRANSPORT CASE GEN5.5
1x CABLE AND ADAPTER KIT INCL. TRANSPORT CASE GEN3/4
1x FILLING & MEASURING BELL HIGH-VOLTAGE BATTERY I12,I15, GEN3/4 PHEV
1x FILLING & MEASURING BELL HIGH-VOLTAGE BATTERY I01,K17
1x ADAPTER CABLE ELECTRIC DRIVE UNIT GEN5
1x ADAPTER KIT/ TRANSPORT SUITCASE GEN5 PHEV
