Today we are fixing a Bosch ABS/ESP control module used on BMW vehicles from the late 1990s to early 2000s — commonly fitted to E38 (7-Series), E39 (5-Series), and E46 (3-Series) models.
Known as ABS module repair / rebuild for BMW.
Customer brought it into the shop after they tried to repair it themselves. You can see jumper wire and broken connection lines. The casing has been fixed with resin, was probably damaged when attempted to open.
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The board used in these units is a hybrid circuit (a ceramic substrate with thick-film resistors and surface-mount ICs).
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The black wire you see might be a test connection or a repair jumper — not factory-original.
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The fine bond wires along the connector edge carry signals between the hybrid substrate and the external connector pins. (common failures)
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There’s a conformal coating or resin around the components for moisture protection.
These Bosch modules are known for:
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Bond wire fatigue or breakage (causing intermittent loss of wheel-speed or communication signals).
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Internal solder cracks at the hybrid-to-connector junction.
Common Repairs
Typical repairs include:
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Rebonding or micro-soldering broken connector wires.
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Resealing the module after rework.
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Testing via diagnostic bench tools (e.g. Bosch KTS, Autologic, or BMW DIS/INPA).
Note, the connector wires do not take regular solder, best bring it to the shop for us to do the repair.