# Rear Parking Aid Fault



## Will77 (Jul 5, 2019)

Hi everyone,

I have a 2012 Audi TTS and the rear parking aid has just stopped working. It no longer beeps when engaging reverse or when you are reversing towards things. I am not mechanically minded but more than capable if pointed in the right direction! I have checked the fuses, they all seem OK and the reverse lights still come on when you put it into reverse. If anyone can help / steer me towards the fault i would be much appreciated!


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## SwissJetPilot (Apr 27, 2014)

Unless someone comes up with a definitive fix, best bet is to get it scanned with VCDS. At least it will point you in the right direction.

SSP382 has some good information on the parking sensors -
View attachment 1

If you have access to a VCDS, you can follow up with the error code for a possible solution as is listed below from the Ross Tech website. This is just one example, you can usually search their webiste by the error code that shows up during the scan - 
http://wiki.ross-tech.com/wiki/index.php/01549

_*01549 - Supply Voltage for Parking Aid Sensor: Short to Ground*
*Possible Symptoms*
- Malfunction Indicator Light (MIL) ON
- Parking Aid not working
*Possible Causes*
- Fuse(s) faulty
- Wiring and/or Connector(s) from/to Parking Aid Sensor(s) faulty
- Parking Aid Sensor(s) faulty
*Possible Solutions*
- Check Fuse(s)
- Check Wiring and/or Connector(s) from/to Parking Aid Sensor(s)
- Check/Replace Parking Aid Sensor(s)
- Check Measuring Value Blocks (MVB) for Supply Voltage
*Special Notes*
One faulty sensor can cause this DTC and drop the Sensor Voltage Supply MVB reading. Unplugging the front -or- rear wiring harness to eliminate 4 sensors at a time is advised during the diagnosis. Make sure to cycle the ignition off and back on before evaluating the MVBs. After the front -or- rear of the vehicle are determined to be problematic it is recommended to unplug the senors one at a time to see which one crashes the Sensor Voltage Supply MVB reading._

Some of the other Parking Assist faults could show up in a scan result like this -

Address 76: Park Assist Labels: 1J0-919-283.LBL
Part No: 1J0 919 283 A
Component: Einparkhilfe 0001 
Coding: 00013
Shop #: WSC 31414 
VCID: 2C57F6F5DC0DB55EF2-5106

6 Faults Found:
01545 - Sensor for Parking Aid; Rear Left (G203) 
28-10 - Short to Plus - Intermittent
01545 - Sensor for Parking Aid; Rear Left (G203) 
31-00 - Open or Short to Ground
01546 - Sensor for Parking Aid; Rear Mid-Left (G204) 
28-10 - Short to Plus - Intermittent
01546 - Sensor for Parking Aid; Rear Mid-Left (G204) 
31-00 - Open or Short to Ground
01547 - Sensor for Parking Aid; Rear Mid-Right (G205) 
31-00 - Open or Short to Ground
01548 - Sensor for Parking Aid; Rear Right (G206) 
31-00 - Open or Short to Ground


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## John949 (Apr 12, 2017)

Beg, borrow or steal a VCDS system if you intend to do any serious maintenance of the car. Scanning the Parking aid system is where most of us would start (as SJP says). If you want to do it the hard way then:

Fuse SC7 is the only fuse in circuit for later models (fuse box C is the one in the end of dash). Pre 2009 have 4 fuses SC7, SD2, SF6 & SF8.
The control module is In luggage compartment at rear, right side, below side trim

The warning buzzer is Behind right rear speaker trim in a coupe & Behind left rear bulkhead trim in a roadster.

I think you know where the sensors are!

I doubt you problem is related to the sensors as sudden failure of all 4 is unlikely. You say the reverse lights work so that should eliminate the reverse switch and part of the CAN Bus. That leaves power to the control module, the control module itself,the rest of the CAN Bus, the warning buzzer and all the associated wiring. Scanning it is starting to look more attractive by the minute isn't it?


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## IPG3.6 (Sep 5, 2015)

My bet is a dead module, or some little critter has gone in and eaten something or water ingress causing a short.

But like everyone else has said - get a scan and that'll point you in more of an accurate direction.


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## N6SSA (Mar 29, 2009)

Hi. I have this code 01549 error due to low Supply Voltage for the Parking sensors.
I have checked the MVBs and disconnected the parking sensors in turn and reset ignition between each check. I am only showing about 6.7V at the Sensor Voltage Supply MVB, (Should be between 10V and 14V). I have removed the rear bumper and I get the same voltage if I have all sensors connected or any of them connected or non of them connected.

While I was in VCDS I noticed that the Coding is 00000B which translates as No Trailer Hitch, Manual Transmission, LEFT hand drive, Audi TT 8J

If I try to change it to RHD, even with the Security code accepted, then I get an out of range error.

But back to the main issue - the 01549 error. Does it mean that the Parking Aid Control Unit (in front of right rear light cluster) is Kaput?

Address 10: Park/Steer Assist (J446) Labels:. 8P0-919-475-7X1.clb
Part No SW: 8P0 919 475 F HW: 8P0 919 475 
Component: PARKHILFE 4K H06 0102 
Revision: 11001001 Serial number: 52330824807261
Coding: 00000B
Shop #: WSC 01236 758 00200
VCID: 41897F9ED8168047EA-8014

1 Fault Found:
01549 - Supply Voltage for Parking-Aid Sensor 
009 - Open or Short to Ground
Freeze Frame:
Fault Status: 01101001
Fault Priority: 3
Fault Frequency: 1
Reset counter: 244
Mileage: 112997 km
Time Indication: 0
Date: 2020.03.04
Time: 14:06:16

Freeze Frame:
Temperature: 9.0∞C


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## MT-V6 (Jan 11, 2015)

I think they are all coded LHD from what I've seen, not sure what difference it would make anyway

Have you narrowed it down to a particular sensor? With it in reverse, ignition on, can you hear a faint clicking from each sensor if you listen up close?


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## IPG3.6 (Sep 5, 2015)

MT-V6 said:


> With it in reverse, ignition on, can you hear a faint clicking from each sensor if you listen up close?


Do this or pop your finger on it too - you should feel them clicking rhythmically


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## N6SSA (Mar 29, 2009)

Hi. Ignition on, in reverse. I get long beep indicating a problem. I can feel and hear nothing from any of the sensors.

I'm only getting 6.7V on the sensor voltage Measuring Block, irrespective of how many sensors are connected - all, some, none.


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## MT-V6 (Jan 11, 2015)

Yes that is low, mine are 11.7 / 14 volt with engine off / on

What is your module supply voltage. Mine is the same as above

If the module supply is low I'd guess it might be wiring but would be odd as it's powered direct from a fuse

If supply voltage is fine it is probably the module at failt


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## N6SSA (Mar 29, 2009)

Yes Module Supply Voltage is fine. It's just the Sensor Voltage Supply MVB which is low. 
If I was to disconnect the Sensor Plug at the Module and recheck, would that have any impact on the diagnosis?
Thanks


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## MT-V6 (Jan 11, 2015)

I'm not sure how it would really, apart from making sure the connector is clean and fitted properly


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## N6SSA (Mar 29, 2009)

Just to report back, I replaced the module and all is well.

Edited: Started rambling about an error which is not at all related to this module.


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