ECU Clone / TCU Clone Workflow

Purpose

Bring a replacement ECU or TCU into service so it behaves identically to the original module it replaces, from the vehicle's point of view. See 01_Knowledge_Base/ECU_TCU_CLONE_CONCEPTS.md for background concepts.

Prerequisites

Confirmed authorization for the vehicle and both the original and replacement/donor module.
Exact part number and hardware/software revision match (or documented compatibility) between original and donor.
A readable original, or a previously-stored known-good backup if the original is no longer readable (e.g. dead MCU).
Understanding of whether this platform requires an ISN re-sync or equivalent security pairing step — see 04_Workflows/ISN_OPERATIONS_WORKFLOW.md.

Required adapters

Same adapters as 04_Workflows/EEPROM_READ_WRITE_WORKFLOW.md / 04_Workflows/MCU_READ_WRITE_WORKFLOW.md, matched to the specific ECU/TCU's memory devices.
Bench harness/breakout matching the module's connector, if bench power-up (rather than chip-off read/write) is used.

Wiring references

Use the connector pinout documented for the exact module part number; ECU/TCU connectors vary significantly even within one vehicle platform across model years.

Safety notes

Confirm hardware revision compatibility before starting — physically identical connectors do not guarantee compatible internal hardware.
Treat any immobilizer/security-pairing data within the module under 07_Authorized_Key_Immobilizer_Work/README.md governance.
Keep the failed original module and its last readable backup even after a successful clone, in case the replacement needs re-verification later.

Procedure

Identify — confirm exact part number, hardware revision, and calibration/software version of both original and donor.
Acquire — read the original (dual-read + hash) or retrieve the last known-good backup.
Transfer — write vehicle-specific configuration/calibration data to the donor module, following that module's data-region layout.
Security/pairing — determine whether this platform requires a separate pairing/sync step (see 04_Workflows/ISN_OPERATIONS_WORKFLOW.md); do not assume it happens automatically with a data copy.
Verify — confirm the replacement communicates/starts correctly and that its self-checked firmware checksum is valid.

Common failures

Part-number/hardware-revision mismatch between original and donor.
Calibration data copied but the pairing/security step skipped or performed in the wrong order relative to the data write.
Checksum not recalculated after manual edits, causing the module to reject its own image at boot.
Working from a single, unverified read of a failing/intermittent original instead of a dual-verified read.

Recovery procedures

If the donor module fails to start the vehicle after cloning, first re-verify the data write against the source backup (byte-for-byte) before assuming a pairing/security issue.
If pairing fails and the platform has an "all keys lost"/recovery procedure, that is an authorized-key-learning matter — see 04_Workflows/AUTHORIZED_KEY_LEARNING_WORKFLOW.md and 07_Authorized_Key_Immobilizer_Work/README.md, not a generic clone retry.
Preserve the donor's pre-clone factory state backup (read before any writes) in case the clone needs to be reversed for warranty/return purposes.

01_Knowledge_Base/ECU_TCU_CLONE_CONCEPTS.md
04_Workflows/ISN_OPERATIONS_WORKFLOW.md
04_Workflows/VIN_MIGRATION_WORKFLOW.md
07_Authorized_Key_Immobilizer_Work/README.md

3.5 KiB Raw Blame History