Overview

This TPMS (Tire Pressure Monitoring System) control unit from Siemens VDO is an RF homologation module used on certain Citroën and Peugeot vehicles. The unit receives wireless signals from wheel sensors, evaluates tire pressure and system status, and communicates warnings to the vehicle instrument cluster. It is a direct-replacement electronic module typically referenced by OEM code 9655140080 and secondary code S120231100E.

Benefits For Professional And DIY Repairers

Designed for workshops and experienced DIY mechanics, this unit restores TPMS functionality after control module failure. Replacing a faulty TPMS control unit eliminates false low-pressure warnings and re-enables accurate monitoring of individual wheel pressures. The module is suitable for technicians who can access vehicle diagnostics to perform sensor relearn and system checks.

How The Part Works And What It Does

The module acts as the RF receiver and processing unit for the vehicle TPMS. It collects radio transmissions from each wheel sensor, verifies their IDs and pressures, filters signal noise, and sends processed data to the vehicle’s cluster via CAN or dedicated wiring. In addition to pressure monitoring, it may provide sensor battery status and signal quality information to the car’s onboard systems.

Replacement And Service Notes

Typical replacement steps: safely disconnect the vehicle battery, locate and remove the faulty TPMS control unit (often mounted in the boot area, behind trim panels or under the rear seat depending on model), disconnect the electrical connector and any antenna leads, fit the new unit and secure it in the original mounting position, reconnect connectors and battery. After mechanical installation, perform a sensor relearn or initialization using a diagnostic tool so the control unit recognizes all four wheel sensors and communicates correctly with the cluster. Finally, verify system operation by checking for absence of fault codes and confirming normal pressure readings for each wheel.

Technical Information

• Manufacturer: Siemens VDO
• Model: TPMS Control Unit / RF Homologation Module
• Product Codes: 9655140080
• Other Numbers: S120231100E

Installation Recommendations

• Always disconnect the negative battery terminal before starting work to avoid short circuits and protect electronic modules.
• Handle the unit as an electrostatic-sensitive device; avoid touching connector pins and PCB areas.
• Keep mounting position, connectors and antenna leads intact and correctly routed to preserve RF reception.
• Use an appropriate diagnostic tool (PSA DiagBox or a compatible TPMS/scan tool) to perform sensor relearn/initialization and to clear stored fault codes.
• After installation, perform a road test and re-scan the system to confirm all sensors are detected and pressure readings are stable.

Why This Part Commonly Fails

Common failure modes include water ingress and corrosion of connectors, internal component degradation due to age or thermal cycling, antenna or RF front-end failure that prevents reception of wheel sensor signals, and damage from improper handling during repairs. Electrical transients (for example, from jump-starting with incorrect polarity) or long-term exposure to moisture and road salt can accelerate failure. Sensor battery failures or broken sensor valves can also produce symptoms that appear to be control unit faults, so a thorough diagnostic approach is recommended.

Compatibility And Typical Applications

This unit is commonly associated with Peugeot and Citroën vehicles using Siemens VDO TPMS systems; it is frequently referenced for Peugeot 407 applications (see product code 9655140080). Ensure you match the product code on the unit with the vehicle’s original part number to confirm fitment before installation.

Notes For Professional Use

Replacement of the TPMS control unit is straightforward for a trained technician but requires diagnostic equipment for finalization. Proper relearn and verification are essential to restore full TPMS functionality and avoid nuisance warnings or missed alerts.