lemonjellyking

Hi all, I’ve got a 2015 Audi A5 with a recurring issue related to the power steering control module (J500). The fault is U140A00 – Terminal 30 open circuit, and it disables the power steering when it happens. It's happened twice now under very specific circumstances where I've rode the clutch for maybe a second longer than I should have, before selecting third gear. The engine cuts outs mimicking a stall, and then the power steering is gone until a garage resets the fault. Audi performed an initial repair for £900, replacing some of the wiring. They reset the fault using their diagnostic tool (probably ODIS), and the steering worked fine afterwards — but the fault returned a week later, and they now want £3,500 to replace the steering rack, which I’m not convinced is necessary. If the steering functions perfectly once the fault is cleared, that suggests the issue is superficial — possibly a false positive or transient electrical glitch rather than mechanical failure. They've reset the fault again, and all is currently working, but it will fail again. My goal is to buy a reliable OBD2 device that can clear this fault when it arises, ideally one that can access the J500 module directly and possibly run some diagnostics too. Has anyone successfully used a consumer-level tool (OBD11, VCDS, Carista, etc.) to clear this specific fault? Would love to know: Which device you used If it could access the J500 module / steering assist If it actually cleared the U140A fault (and didn’t just read it) Thanks in advance! For anyone interested, this is Audi's diagnostics report: SYS01_x_1_0715_21_GW_Info_00000 Functional checks (2) Function test 3: SYS_8T_45_____1_0618_21_J500_FSP_00021 Time required (TU): 0.3 Result: X Time required (TU): 0.3 ( 2025-04-30 07:54:32 - 2025-04-30 07:54:41 ) Mouse clicks: 2 Keyboard entries: 0 Test step: Preparation steps Test step: Read fault memory Action: Message In the ABS control unit -J104 fault 01309 Power steering control unit / Read fault memory is stored. Test step: Read fault memory Action: Message Faults are entered in the fault memory of the Power steering control unit -J500. For further fault treatment work through the test plan. Test step: Caster Action: Message End of test. Function test 4: SPG_8K_48_____1_0511_SPGSVERSORGUNG_KL_30_A4_A5_00021 Time required (TU): 3.1 Result: OK Time required (TU): 3.1 ( 2025-04-30 07:54:51 - 2025-04-30 07:56:24 ) Mouse clicks: 14 Keyboard entries: 0 Test step: Preparation steps Test step: Brief description of test Action: Message Using this test program, you can check the following component/system: Terminal 30 Required test equipment: Possibly VAG 1594/13 CLAMP ON TEST PROBES from VAG 1594 A Connector Test Kit. Road test if necessary Test step: DTC memory Action: Message The DTC memory of the Power Steering Control Module -J500- stores the malfunction U140A00 Terminal 30 open circuit . Function call: jxxx_xx_1_0416_21_DTCs_pruefen_00000 Test step: DTC memory Test step: Check fuse Action: Selection Was the fuse for terminal 30 faulty and was it replaced? Input: No Test step: Check harness connector/wire 1 Action: Message - Check harness connector of Power Steering Control Module -J500-. - Check the connector for: Correct seating/loose contact; Bent and pushed-in pins; Widened connector terminals; Water entry, contact corrosion; Crushing, kinking and abrasion of the connected wiring. Action: Selection Is there a malfunction? Input: No Action: Selection - Check Ground (GND) connections of steering according to wiring diagram. - Check wiring for short circuit to ground. Is the wiring OK? Input: Yes Action: Message The wiring and harness connectors are OK. Control unit communication (UDS) Control unit: Power steering (LL_SteerAssisUDS) Job status: OKAY Service: SinglJob_ChangDiagnSessi Request parameters: Response parameters: Function call: j500_8R_48_____3_0111_21_fsp_loeschen_00021 Test step: Mode change Control unit communication (UDS) Control unit: Power steering (LL_SteerAssisUDS) Job status: OKAY Service: SinglJob_ChangDiagnSessi Request parameters: Response parameters: Test step: Read DTC memory Action: Message Next, the DTC memory of the Power Steering Control Module -J500- will be checked again. Action: Message DTC memory is being checked. Please wait Control unit communication (UDS) Control unit: Power steering (LL_SteerAssisUDS) Job status: OKAY Service: SinglJob_ReadAllDTCFreezFrame Request parameters: Response parameters: Control unit communication (UDS) Control unit: Power steering (LL_SteerAssisUDS) Job status: OKAY Service: SinglJob_ReadAllDTCFreezFrame Request parameters: Response parameters: Action: Message The DTC U140A00 Terminal 30, open circuit is not stored in the DTC memory of the Power Steering Control Module -J500-. Test step: Road test Action: Message To check the function, perform a road test while observing the following instructions. - Drive off-road if possible.