J538x – 2.0L MQB Fuel Pump Control Module

• Plug-n-Play replacement for the factory Volkswagen/Audi Fuel Pump Control Module (J538)
• Eliminates diagnostic trouble codes (DTCs)
• Fully configurable with easy to use TorqVFM PC software
• TorqVFM software provides live-viewing, data-logging and playback of ECU-commanded vs. Pump-actual duty helping to diagnose fuel system or ECU tuning issues
• Replaces the following VAG J538 Modules: 
• Designed, tested and made in Canada

Torqbyte J538x module is a complete replacement for the factory VAG fuel pump PWM control module J538 in vehicles already equipped with a Torqbyte PM3 High Power LPFP driver and a Torqbyte VAG PnP Harness. J538x is supplied with Plug-n-Play wiring adapters that connect directly to factory vehicle wiring on one side and to the Torqbyte VAG PnP Harness on the other side. The J538x wiring comes with a genuine VAG oval grommet Part No. 6Q0 971 905 that provides the same sealing as the factory module. The J538x is housed in a rugged extruded aluminum enclosure that makes it suitable for installation under the rear seat.

In the factory configuration the OEM fuel pump control module (J538) receives pump duty commands from the ECU and converts them to actual pump duty. The relationship between the ECU-commanded duty and the actual pump duty is called Slope and is fixed for each module part number. There is no way to monitor the ECU-commanded duty or the actual pump duty forcing users to sift though VCDS logs when fueling problems need to be diagnosed.

Torqbyte J538x also receives its commands directly from the ECU but provides the user to program in their own custom Slope values that are less or more aggressive than the nominal OEM Slope. (Note: J538x comes pre-programmed with from the factory with the optimal Slope characteristic so no programming is required prior to installation and operation).

J538x is also equipped with a USB connector that allows it to communicate with a PC running our free TorqVFM software. With this software, the user can test and configure the unit as well as live view or log ECU-commanded duty vs. actual pump duty. J538x can be invaluable for diagnosing difficult fueling issues such as inability of the actual LPFP pressure to reach or or stay at the commanded target level.

TorqVFM Software

The J538x unit ships from the factory ready to install. Nothing is required to use it. However, if advanced features and functions are required, more information on the accompanying TorqVFM software can be found HERE.