Audi Q3 Transmission indicator PRNDS Flashing

Most common problem of audi Q3 transmission indicator PRNDS flashing in automatic transmission gear box is due to malfunction in the mechatronic fitted in the gear box. when these PRNDS gear position indicator light start flashing, automatic gear box will go under limp mode. at this position car can not move forward or reverse, due to limp mode of gear box. these fault code may be intermittently due to low voltage battery or voltage fluctuation in electrical system or due to CAN system disturbance. the same problem can be seen in all Q series like Q3, Q5, Q7.

Causes of Transmission indicator PRNDS Flashing :

  • the measure cause of this kind of problem is failure of mechatronic fitted inside the automatic gear box. which control the whole gear changing process by receiving signal from all the other control modules. if mechatronic goes under limp mode or fail due to any reason this problem can be seen.
  • mechatronic fail due to many reasons like low oil pressure, dirty oil, metal present in oil and also electrical short circuit in it.
  • Disturbance in CAN system which carry message from one module to other module.
  • Loose connection at mechatronic control module.
  • faulty engine control module.
  • low voltage at mechatronic.

solution of Transmission indicator PRNDS Flashing:

  • Repair damage wiring harness.
  • replace faulty engine control module.
  • make proper connection at fuse box.
  • Repair or replace faulty mechatronic.
  • perform basic setting of gear box.

Common Symptoms :

  • Transmission gear position indicator light will start flashing.
  • vehicle will not move forward or revers.
  • fault code will store in engine control module.

how to trouble shoot this problem :

  • to solve this problem mechanic should start diagnosing this fault code by scanning the system. check the status of fault code weather it is present in intermittently or active static. if it is in intermittent status than try to delete it and take a trial of vehicle. it might be gone if it does not then go further test. if fault code is present in the system in active static then it might be serious to solve.
  • check the wiring harness, measure voltage supply, CAN wiring at mechatronic and engine control module. check engine control module for internal short circuit due to water at the place of ECU. engine control module is fitted below the wiper grill, where water store most of the time. wiring loop of engine control module come from left side under the wiper grill in which there are wiring loop which get damage due to water.
  • Check voltage supply at ECU and mechatronic in gear box. most of the time this problem occurs due to loos connection in the fuse box located at the engine compartment. if engine control module, mechatronic control module and its wiring harness is good. than go to check for the mechanical problem inside the gear box.
fuse box
Engine control module

Common mistake occurs during trouble shooting this problem :

  • most of the time mechanic change the gear box without finding the reason behind this fault code. in some cases this fault code store in TCM control module due to low oil level in the gear box. in this case the problem can be solve by filling the oil at require level.
  • also sometime this kind of problem can be solve by performing basic setting of mechatronic.

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