Audi Q4 FZ — Problems & Common Faults

Permanent-magnet synchronous motor with hairpin winding on the rear axle, part of the drive family from the MEB platform with a 400-volt electrical system. On mechanically identical sister models from the same group with a comparable motor concept, oil loss and bearing noise at the rear axle have occasionally been documented from high mileages onward (roughly 180,000 to 210,000 kilometres) – a precautionary oil change around 100,000 kilometres is considered a sensible precaution, though not mandatory. One recall concerned the onboard charger for the 12-volt battery: moisture could penetrate through an insufficiently coated circuit board, so the battery stopped charging – in the worst case this risked a loss of drive power while under way, with warning messages appearing on the instrument cluster beforehand. Regenerative braking works solely through the rear motor and can decelerate purely electrically up to around 0.15 g, with the handover to the mechanical brake barely noticeable.

• !! Recall: electric parking brake can fail

  Software fault in the brake control unit can under certain conditions cause failure of the electric parking brake. Approx. 110,000 vehicles worldwide affected (built 2020–2023). KBA number 14877R, manufacturer code 454R.

  Symptoms: Red parking brake warning light not constant, vehicle can roll away. Two damage cases documented, no injuries.
  0–0 $
  Ad Bremscontrol unit Q4 e-tronEPB Software Update
• !! MMI infotainment freezes or reboots from 5,000 km

  The MIB3 infotainment freezes particularly often at temperatures below approx. 3.5 °C. Black screen or complete reboot during driving. Audi confirmed the fault as a defect in a control unit and had no solution for a long time.

  Symptoms: Black centre screen during driving, navigation disruption, no sound. Reboot by pressing the volume knob for a long time needed.
  0–500 $
  Ad MIB3 control unitMMI Displayeinheit Q4
• !! 12V battery deep discharge during standstill from 30,000 km

  The 12V electrical system deep-discharges during extended standstill (from around 3–4 weeks) as the DC/DC converter system does not reliably keep the vehicle awake. The vehicle then no longer starts and must be recovered.

  Symptoms: Vehicle completely unresponsive after standing, no response to key fob, parking brake remains applied. Jump start needed.
  150–400 $
  Ad 12V AGM battery Q4 e-tronDC-DC Wandler MEB

+ 3 more engine weaknesses + vehicle weaknesses

Rear-axle motor from the APP310 series within the MEB platform – a permanent-magnet synchronous motor with hairpin winding and a 400-volt electrical system, also fitted in several mechanically identical sister models from the same group. There, oil loss and bearing wear have occasionally been documented from high mileages onward (roughly 180,000 to 210,000 kilometres); how serious this is in individual cases is debated among specialists. A precautionary oil change around 100,000 kilometres using the specified special oil grade costs little and is considered a sensible precaution. A separate recall concerned the onboard charger for the 12-volt battery: moisture could penetrate through an insufficiently coated circuit board, causing the battery to stop charging and, in the worst case, risking a loss of drive power while under way. Independent tests praise the drive for strong, cleanly modulated propulsion; purely electric deceleration through the rear motor reaches around 0.15 g.

• !! Recall: electric parking brake can fail

  Software fault in the brake control unit can under certain conditions cause failure of the electric parking brake. Approx. 110,000 vehicles worldwide affected (built 2020–2023). KBA number 14877R, manufacturer code 454R.

  Symptoms: Red parking brake warning light not constant, vehicle can roll away. Two damage cases documented, no injuries.
  0–0 $
  Ad Bremscontrol unit Q4 e-tronEPB Software Update
• !! MMI infotainment freezes or reboots from 5,000 km

  The MIB3 infotainment freezes particularly often at temperatures below approx. 3.5 °C. Black screen or complete reboot during driving. Audi confirmed the fault as a defect in a control unit and had no solution for a long time.

  Symptoms: Black centre screen during driving, navigation disruption, no sound. Reboot by pressing the volume knob for a long time needed.
  0–500 $
  Ad MIB3 control unitMMI Displayeinheit Q4
• !! 12V battery deep discharge during standstill from 30,000 km

  The 12V electrical system deep-discharges during extended standstill (from around 3–4 weeks) as the DC/DC converter system does not reliably keep the vehicle awake. The vehicle then no longer starts and must be recovered.

  Symptoms: Vehicle completely unresponsive after standing, no response to key fob, parking brake remains applied. Jump start needed.
  150–400 $
  Ad 12V AGM battery Q4 e-tronDC-DC Wandler MEB

+ 2 more engine weaknesses + vehicle weaknesses

All-wheel drive combining an asynchronous machine on the front axle with a permanent-magnet synchronous motor from the APP310 series on the rear axle (MEB platform, 400-volt electrical system). The front machine can be decoupled under light load, reducing friction losses and improving efficiency. On the mechanically identical rear motor, sister models from the same group have occasionally documented oil loss and bearing wear from high mileages onward (roughly 180,000 to 210,000 kilometres); a precautionary oil change around 100,000 kilometres is considered a sensible precaution. One recall concerned the onboard charger for the 12-volt battery: moisture could penetrate through an insufficiently coated circuit board, causing the battery to stop charging, with a risk of losing drive power while under way in the worst case. Purely electric braking on the all-wheel-drive version reaches nearly 0.3 g, prioritising the rear axle and involving the front axle only in rare situations – the handover to the mechanical brake is barely noticeable.

• !! Recall: electric parking brake can fail

  Software fault in the brake control unit can under certain conditions cause failure of the electric parking brake. Approx. 110,000 vehicles worldwide affected (built 2020–2023). KBA number 14877R, manufacturer code 454R.

  Symptoms: Red parking brake warning light not constant, vehicle can roll away. Two damage cases documented, no injuries.
  0–0 $
  Ad Bremscontrol unit Q4 e-tronEPB Software Update
• !! MMI infotainment freezes or reboots from 5,000 km

  The MIB3 infotainment freezes particularly often at temperatures below approx. 3.5 °C. Black screen or complete reboot during driving. Audi confirmed the fault as a defect in a control unit and had no solution for a long time.

  Symptoms: Black centre screen during driving, navigation disruption, no sound. Reboot by pressing the volume knob for a long time needed.
  0–500 $
  Ad MIB3 control unitMMI Displayeinheit Q4
• !! 12V battery deep discharge during standstill from 30,000 km

  The 12V electrical system deep-discharges during extended standstill (from around 3–4 weeks) as the DC/DC converter system does not reliably keep the vehicle awake. The vehicle then no longer starts and must be recovered.

  Symptoms: Vehicle completely unresponsive after standing, no response to key fob, parking brake remains applied. Jump start needed.
  150–400 $
  Ad 12V AGM battery Q4 e-tronDC-DC Wandler MEB

+ 2 more engine weaknesses + vehicle weaknesses