Automotive Blog

Volvo FL AdBlue Fault A Volvo truck was presented to our workshop today, the driver had reported a fault that the instrument cluster was showing a warning for AdBlue system failure.  Naturally the first action to take was to carry out a diagnostic code read. However when we attempted to code read the AdBlue control module (ECU) it was found to be not communicating. Instead carrying out a fault code read of the engine control unit was found to be useful, here are the results: MID(128):Injection ECU, PSID:229, FMI (9):Data update frequency Connection problem with the UDS (AdBlue pump module) ECU on the SAE J1939 CAN bus data line. It became apparent that the AdBlue system was not accessible due to a CAN bus fault.  The next step was to monitor the CAN network at the AdBlue ECU. As we explained in our previous CAN fault finding article , we first test the CAN network with the wiring block disconnected from the AdBlue ECU. The oscilloscope was ...

A Quick Look At CAN Network Testing A vehicle arrived at our workshop today on the back of the wrecker. The fault reported was non-start and also the instrument cluster was showing a warning that the vehicle was not recognising that the gearbox was in neutral. Although the tests and fault finding steps in this post are the same for most vehicle CAN networks, the vehicle we were presented with was an 2008 Iveco with a ZF AS-Tronic EcoLite gearbox. The first course of action was to carry out a diagnostic code read on the transmission system, here are the results: Fault Code - 806 - Clutch Actuator Fault Code - 830 - Clutch Position Fault Code - 833 - Clutch Position Open Fault Code - 834 - Clutch Position Closed Fault Code - 900 - Terminal 30 Fault Code - 907 - Relay Circuit 1 Fault Code - 909 - Relay Circuit 2 Fault Code - 865 - Gear Select Fault Code - 896 - CAN Error Message Fault Code - 918 - Clutch Valve 2 Closed This, coupled with the fact that all ...