The Dealer Got It Completely Wrong…Our Diagnosis Exposed the REAL Problem

A BMW X5 (F15) arrived with serious hybrid system issues, almost no electric range, and warnings that made the vehicle undrivable. The main dealer suggested a simple module failure — but the real problem was far more complex than expected.

In today’s video, we perform a full investigation of the high-voltage system, uncover the true reason behind the battery imbalance, strip the complete HV pack, replace the internal modules, rebuild the cooling system, reset programming, and finally take the X5 on a full-cycle road test.

This repair was anything but standard — and the underlying cause is something every hybrid owner should know.

Stay close… this one is packed with diagnostics, deep technical insights, and a surprising ending.
📍 Visit Us:
OGS Mechanics
Units 9–14, Millers Yard
Rear of 28 Long Lane
London N3 2QG

📺 Watch Our Repairs in Action:
📌 Subscribe on YouTube
→ Weekly EV/Hybrid breakdowns, fixes & full diagnostics

📲 Follow the Behind-the-Scenes Garage Life:
🎵 TikTok:   / ogsmechanics  
📸 Instagram:   / ogs_mechanics  
📘 Facebook: https://www.facebook.com/share/15J54K...

🕒 TIMESTAMPS

0:00 – A different kind of diagnostic today
0:12 – Visiting the customer’s BMW X5
1:41 – Initial scan & first warning signs
2:37 – Electric range shockingly low
3:05 – First drive test
4:02 – Battery state of health revealed
5:26 – Why the electric drive is disabled
6:22 – Calling the customer with the findings
7:58 – Bringing the X5 to the workshop
8:56 – High-voltage battery analysis
11:26 – Stripping the boot & accessing the HV battery
12:27 – Opening the battery pack
14:18 – Removing the first module
15:21 – Why cooling failures destroy batteries
17:05 – Severe capacity degradation explained
19:52 – Removing all six modules
21:32 – Empty battery tray
22:04 – Measuring and balancing replacement modules
22:36 – Beginning the reassembly
23:39 – How BMW module sensors work
24:47 – Rebuilding the battery structure
26:49 – End of Day 1
27:26 – Monday: restarting the repair
28:31 – Final modules installed
29:18 – Voltage test across the full pack
31:38 – HV interlock installed — system ready
32:15 – Clearing codes & first look at the new statistics
33:56 – Battery fully balanced
35:19 – Preparing for full road test
39:05 – On the motorway: real-world range test
41:31 – Still discrepancies…
42:40 – The real software issue discovered
43:59 – Replacing the SME control module
46:55 – Second attempt: proper range test
47:43 – Cell behaviour under low voltage
49:56 – Returning to the garage
50:45 – Final summary on cost and repair
53:07 – Outro & what we learned

#BMWX5 #HybridRepair #HighVoltageBattery #EVRepair #OGSMechanics #BatteryRebuild #HybridSystem #BMWRepair #ElectricDrive #CarDiagnostics #EVWorkshop