Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Checking ECM Version
Following procedure is for checking ECM version using manufacturer scan tool (VAG 1551). Check DTC memory. See RETRIEVING DIAGNOSTIC TROUBLE CODES. Display will read - "RAPID DATA TRANSFER" "SELECT FUNCTION XX". Press buttons -0- and -1- to select "CHECK CONTROL MODULE VERSIONS" function 01. Display will read - "RAPID DATA TRANSFER" "01-CHECK CONTROL MODULE VERSION". Press -Q- button to confirm input. Display will read - "4A0907551AA 2.21 R5 MOTR RHV HS D" "CODING 4". This display can be broken down as follows, see MOTRONIC ENGINE CONTROL MODULE VERSION table. CHECKING ECM VERSION Applications Scan Tool Display ECM Identification (1) 4A0907551AA Engine Displacement 2.21 Liter Engine Type: R In-Line 5 Cylinder Fuel Injection Type: MOTR Motronic Multiport Fuel Injection Ignition Type: RHV Resting High Voltage Distribution Transmission Type: HS Manual Transmission Type: AT Automatic ECM Software: "D" Manufacturers Use Only Coding (Number) (2) 1 or 4 (1) Check with parts for updated versions. (2) For 1 or 4 coding definitions. See ECM CODING.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.