Mercedes-Benz 46-Pin ECU Engine Computer Board Connector – OEM 2112231-1

The OEM 2112231-1 is a high-density 46-pin female connector used in Mercedes-Benz engine control unit (ECU) and engine computer board harnesses. Designed for precision-fit replacement of damaged or corroded ECU connectors on M-class, E-class, and C-class platforms. Available bare or with 30cm pre-wired leads for direct splice installation.

Key Specifications

Why ECU Connectors Fail

High-pin-count ECU connectors on Mercedes-Benz vehicles are vulnerable to terminal corrosion from coolant leaks, oil contamination, and moisture ingress near the firewall. A degraded 46-pin ECU connector causes multiple simultaneous fault codes, engine misfires, limp mode, or complete no-start conditions. Replacing the connector and re-pinning terminals restores full ECU communication and eliminates phantom fault codes.

Variant Guide

• Female – Bare 46-pin housing with terminals for custom wiring repair
• Female 30CM – Pre-wired with 30cm leads for direct splice-in replacement

Installation Steps

1. Disconnect the vehicle battery and allow ECU capacitors to discharge (5 minutes)
2. Locate the 46-pin ECU connector on the engine control module
3. Use a terminal extraction tool to carefully remove each terminal from the original housing
4. Transfer terminals one-by-one into the new 2112231-1 housing, maintaining pin position
5. Reconnect and use a Mercedes-compatible scanner (XENTRY/DAS) to clear fault codes and verify ECU communication

Frequently Asked Questions

Q: What Mercedes-Benz models use OEM 2112231-1?
A: This connector is used on Mercedes-Benz E-Class (W211/W212), C-Class (W203/W204), and M-Class ECU harnesses. Cross-reference your vehicle’s wiring diagram to confirm fitment.

Q: What fault codes indicate a failed ECU connector?
A: Multiple simultaneous P-codes, U-codes (CAN bus communication faults), engine misfires (P030x), and limp mode activation are common symptoms of a degraded 46-pin ECU connector.

Q: Do I need to recode the ECU after replacing the connector?
A: No. Replacing the connector does not affect ECU programming. Clear fault codes after installation and verify normal operation.

Q: Are all 46 terminals included?
A: Yes, the connector set includes the housing and all required terminals. The pre-wired variant has leads pre-crimped.

Q: Can a workshop perform this repair?
A: Yes. This is a standard ECU harness repair performed by auto electricians and Mercedes-Benz specialists. Terminal extraction tools are recommended for clean removal.

Compatible Applications

• Mercedes-Benz E-Class W211 / W212 – ECU engine harness
• Mercedes-Benz C-Class W203 / W204 – Engine control module connector
• Mercedes-Benz M-Class W163 / W164 – ECU board harness
• Mercedes-Benz CLK / SLK – Engine computer connector