MPG displays "ERR", odometer flashes "------"

[rhino6303]

Is it easy to replace the dial assembly ?

 

Today on the drive home...it more than made up for working on the drive up. It flashed most of the way home...

It is really easy. Remove the front lower trim, unplug the electrical connectors and remove the full switch panel. You can then pop out the dial assembly.

[Max Capacity]

It is really easy. Remove the front lower trim, unplug the electrical connectors and remove the full switch panel. You can then pop out the dial assembly.

 

 

Thanks.

[xt2005bonbon]

I thought I suggested to try something like that first

 

 

I wonder if the 'wheel' or rheostat(?) may just need a cleaning. May not be a real rheostat though.

[Max Capacity]

Oh yea, did you really... How soon we old guys forget...LOL

 

On the drive home yesterday while it flashed most of the time I tried playing with the wheel, lights were not on at the time, because it was day time. The wheel had no effect. But at night time, the wheel seems to help...

 

Got to love these cars...

[xt2005bonbon]

Still can't believe these cars are 15 years old..

[Max Capacity]

So I finally got around to emailing my buddy at the dealership parts dept., he's ordering me the Illumination dial. It will be in next week.

 

As for my wagon it had been a long time since the display flashed Err, until earlier this week. So I guess its time to give this fix a try.

[Max Capacity]

Well that didn't work. I put the new dimmer wheel in over the weekend... was fine Monday and Tuesday, today on the drive to work it started flashing Err.

 

On the way home it did it again, I quickly pushed the brightness button then Disp button to the left of the flashing Err and it stopped.

 

We'll see how long this last...

[xt2005bonbon]

then, it is your clock/mpg unit acting up?

[Max Capacity]

So do you really think just replacing that should fix the issue ?

 

I did just pop the cubby out, disconnect the wire connectors, removed the three screws hold the display under the cubby. Peeled back the aluminum tape on the top of the display pod and opened it up. There's a lot of electronics in there.

 

Closed it up, put the tape back on, reinstalled it in the dash, all that took about 10 minutes.

 

It still flashed Err when I started the car.

 

I looked through my local dealers parts web page and couldn't find any listing for the display pod.

 

I'll look through the junkyards next to see if they list them.

[xt2005bonbon]

Well, I am not saying it is bad for sure, but worth checking. Do you have some MAF cleaner? would be worth spraying some at the wire connectors to make sure there is a good connection. Same goes to the connections of the Illumination dial you just replaced.

[Max Capacity]

I did look at the connectors and pins in the display when I had it out, they looked clean. No indication of corrosion.

 

I do have MAF cleaner.

 

It is funny how lowering the lights to 2 or below illumination, stops it from flashing and it goes back to working normal.

 

Turn the head light's off and it will start flashing.

[ehsnils]

At least to me this indicates that there's some kind of voltage issue in the vehicle, if not ground, then voltage loss on the positive side.

 

 

Start with cleaning both battery connectors and replace them if they are bad. Use some corrosion protection on them when connecting them. Also check the separate wire going to the main fuse box under the hood that it's clean.

 

 

Then start diagnostics, use a volt meter and check if there are voltage differences in the vehicle.

 

• Voltage between engine block and chassis (like a strut tower nut). This shall be zero or at least less than 0.01V.
  
• Voltage on the alternator. Should be around 13.6 to 14.4 when engine is running and battery is good. Measure between connector on alternator and engine block.
  
• Voltage difference between positive pole on battery and connector on alternator. Expect some, but should be less than a volt and if the battery is good/fully charged less than 0.1 volt.
  
  • If there's a voltage drop, then check voltage between incoming main fuse and and alternator, then voltage over the fuse. Measure on the screws holding the fuse, not the fuse itself.
    

  [*]Measure voltage between alternator positive (not battery positive) and one of the headlight fuses (Fuse 6 or 7) when the headlights are on. It shall be as low as possible, but if it's over a volt then you have a problem with headlight relay or headlight fuse.

  [*]Measure voltage between alternator and output on fuse SBF-6 (this feeds ignition switch)

  [*]Measure voltage between alternator positive and input+output on fuses 12, 19 and 32. This shall be a low voltage drop only since it's a control voltage. If the voltage drop is over 0.05V then it's time to start suspect the ignition lock being bad. Fuse 12 feeds the BIU.

  • In order to further check this then you may need to drive with a volt meter connected to fuse 12 with a drop-off to see if the voltage changes whenever you have an intermittent problem. If that's the case then it's the ignition lock that's acting up.
    

  [*]Measure voltage between battery negative and the ground wire from the BIU. If there's a voltage difference there then you also have an answer.

Of course this may not solve the problem, I'm just throwing in things to look at to see if the problem can be found.

[Max Capacity]

Thanks for the ideas. This intermittent issue has been happening for over two years now.

 

Today leaving work, Started the car, display read 65F, nice sunny day. A few seconds later Err popped up. 20 minutes into the drive the display began reading normal again and worked fine the remaining 15 minutes to home.

 

Other times it works fine for weeks other times it will show a Err everyday for a few day's.

 

Over the weekend I'll play with my voltmeter and see what I get, I'll check the wire going to the main fuse box to make sure its clean. I have thought about replacing the battery terminals just because they are 15 years old. I do clean them at least once a year. I just did them a couple weeks back when I put new spark plugs in.

[rhino6303]

Well, it was good while it lasted. My "Err" has returned. I'm pretty sure I'm having issues with grounds. My MAF has been having issues as well. I need to dig into all ground locations, clean and reinstall.

[Max Capacity]

I haven't had time to look into the grounds yet, been busy on the weekends doing other things.

 

May be if we had some pictures of where the grounds were, it would be easier to locate and clean them.

 

 

I'll admit, I'm not really good with a voltmeter.

Edited May 27, 2019 by Max Capacity

[bwindle]

I've been lurking this thread for a bit hoping to find a solution to this intermittent issue. Here's an update on our symptoms (over the past ~5 years) and work that's been done on the car (that hasn't solved the issue) a 2007 Legacy Sedan.

Always: "Err" displays on MPG, Trip MPG average, and miles to empty

Always: Cruise control has never worked, mist wiper lever pull stopped working ~2 years ago

Always: Keyless entry has never worked

Occasionally: RPM/MPH gauges pegged at zero, has fuel but reserve light shows and gauge is pegged on empty, blank odo/trip meter, odo displays as "-----"

Only happened once: "Er 55" displayed on odometer

Console issues seem to appear more often when it is humid/rained recently/large temperature swing, but we've definitely had them when it's bone dry as well. Issues disappear at random often on the next trip. Tweaking the illumination dial as others have doesn't change anything.

Work done on the car:

-checked fuses multiple times

-clockspring replaced (hoping to solve the cruise control issue, didn't work)

-battery and battery wires replaced

-alternator and spark plugs/wires/coil replaced

-at least 4 broken ground wires were repaired

-airbag recall

-faulty map light cluster replaced to get rid of airbag warning light

-numerous other non-electrical repairs

 

My mechanic seems to suspect "a circuit board issue" in the console and "has a guy" who repairs these things on some VW's that have common issues with them. I'm not sure we're putting any more non-critical repairs on the car or I would consider giving "the guy" a try or just replacing the entire console and dealing with the odometer being off. The car seems to need a big repair every year so this issue has gotten pushed aside.

 

This is a photo album showing the various symptoms. Hope the info I've shared might help someone else, look forward to hearing about a fix some day

[Max Capacity]

FWIW, I just cleaned the three grounds that are fairly easy to get from the top. The one behind the fuse box on the left front strut tower, just pop the cover off the fuse box by pressing the two clips inward. 10mm ratchet box wrench gets that 15y/o bolt out with ease.

 

Then took a 12mm socket on a wobble end 12" extension and removed the two bolts from that ground bar off the back end of the intake manifold. I found it easier to stand in front of the car and reach in with my right hand to reach the bolts and wires after the bolts were loose.

 

Used a small wire brush on the bar and fender as well as the bolts and wires.

 

I see if that makes a difference over the next few days.

 

Recently the Err has been flashing I'd say 85-90% of the time. When I started the car at work the temp read 32F for a couple seconds then began flashing Err. A few miles later it began reading the correct temp 70F, for a while.

[kaluce]

Check all of your grounds. Specifically the ones that are by your TGVs. If those grounds are loose then you'll get those. I had the same thing awhile back.

 

 

 

Edit: I tossed a bunch on, since grounding the engine is good, and a few more grounds won't hurt. Make sure you have a few different grounds on the engine. I know there should be two under the body (driver and passenger frame rail that connect under the heads), one's by the dog bone/transmission, 2 big ones by the driver side TGV, the battery itself, and I think there are's one near the water pump.

 

 

 

I tossed some wherever I could. so long as it's stranded wire and you put dielectric grease on top of any exposed ground cables (like crimps) and screws so you don't get too much corrosion, you should be fine. NY snow rotted ALL of my grounds under the car. I used 10ga and included a service loop, which is honestly probably overkill.

Edited May 29, 2019 by kaluce
expanded on my answer

[Max Capacity]

Well its different today after cleaning the three ground locations last night.

 

After reading fine for the first 29 miles on the drive to work, it began to read a steady Err, no flashing. A few seconds later it would go back to reading correctly. Will take a look after work....may be clean the grounds better...

 

I thought a put a link to the service manual page that talks about this display showing Err in here the other day. I wrote the page number down on a note by my home PC, I'll revisit that tonight.

[Max Capacity]

Here is from page 5990 in the 2005 service manual,

 

2. Clock Unit

A: GENERAL

The clock unit display can be switched to indicate outside air temperature, fuel efficiency, remaining

travel distance or continuous driving time, by operating a button. The DISP button is used for switching

the display, and the indicated information switches in the following sequence each time the button

is pressed: outside temperature → fuel efficiency at the instant → average fuel efficiency →

remaining travel distance → continuous driving timeThese data are sent from the combination

meter by means of digital communication. This clock unit is provided with a function to automatically

display a failure; if the accessory power circuit is open it displays “Acc”, and if the ignition power

circuit is open it displays “ign”.If an abnormality is detected in the communication between the combination

meter and clock unit or in the received data, “Err” is displayed.If no data can be received,

“Err” will always be displayed even when the indication is switched with the DISP button, but when

only a specific data is not received, “Err” will be displayed only when the indication is switched to

display that data. For example, if outside temperature data is not received “Err” will be displayed

only when the thermometer feature is selected, and other indications such as the fuel efficiency

meter will be displayed normally.

 

So for now the Err is steady when it does come on for a few seconds, I can't select a different reading when the Err is there. After a short while may 10 seconds or so, the reading comes back, for a while.

 

I'll go out and clean the ground behind the fuse box again. Then see what happens tomorrow.

 

Just took some old 220 emery cloth and cleaned the fender and matting side of the terminal. Wire brushed the bolt again, got a lot of rust dust off the threads. Putting it back on noticed the wires in the terminal look greenish corrosion. Thinking about gutting the old terminal off and replacing it.

 

Just want to do this one step at a time.

Edited May 30, 2019 by Max Capacity

[ehsnils]

Seems like a good idea to take it step by step.

[Max Capacity]

Display worked great until about half way on the drive home. It switched to a steady Err. When traffic got a little lighter a few minutes late I turned on the parking lights and rolled the dimmer to 0.0 the display came back, I rolled the dimmer back up to 5, turned off the parking lights and is was fine for the rest of the ride home.

 

Mowed the lawn after work, may be tomorrow after half a day at work I'll crimp on a new terminal on that ground wire behind the fuse box.

[xt2005bonbon]

next time it gives you the err message, can you see what happens while you change the dimming?

[Max Capacity]

I believe nothing unless I have the head lights or parking lights on.

 

That's why yesterday I just turned on the parking lights using the headlight switch so all the dash lights come on.

 

Next time, I'll try using that switch on top of the steering column.

[xt2005bonbon]

still give it a try to confirm it does nothing.