Hi all,
I am used to getting few or no reply but this time I really need more inputs than last time.

My instrument cluster has no gauges working. All other elements are OK, that means when I turn the ignition key to position 2, all warn signals for ABS, BRAKE, ETS, Seat belt, CHECK ENGINE are on. After starting the engine they are off as expected, except for the parking brake signal. (pic 1 & 2)

Backlight illumination for headlight, as well as turn signal, high beam are working fine. All pixel displays for trip odometer, odometer, outside temperature and clock are on and no missing pixel.

The big issues are the needles of the gauges for engine temperature, fuel level, speed (when moving) and rmp (pressing gas pedal at neutral position "P"), all 4 needles are dead. The needle for speed vibrates a little but does not leave the resting position.

I replaced the cluster with a used but otherwise supposedly working one, same error. Then someone suggested that the relay unit K40 could be the cause; I bought a new one from autohausaz.com, replaced the old one today without success (pic 3). I also made sure that the connectors are firmly attached to the cluster, reached into the cavity behind the connected cluster and wiggled every cable harness to see if there is some loose contact.

Now I really do not know what to do. Normally when I got no reply I accept quietly that my question is either stupid or difficult , now I am giving it another try and hope for some help.

In pic 4 is the wiring diagram for the group of needles, it is not clear to me as to which pin from the connector goes to which gauge.

If I had to take my car to dealership, what do you think it will cost me?
Please give your comments, every input is highly appreciated, be it a sympathy or consolation

 

I removed the cluster and measured the voltage at the two connectors. The first picture show the measurement of the left connector, the second picture for the right connector:

Left connector has power only at pin C1 (11.6 V) and pin L2 (7.47V) and that is suspicious too few pins.
Right connector has power at pin A6, 8, 9, 11 and B3.

The minus sign "-" at the pins means 0.0V was measured, probably ground.

Can someone interprete the measurement, is power missing at some pin? especially of the left connector?

 

New voltage measurement at right connector A-B with engine hot and running, headlight on, applying middle pressure on gas pedal .

A6: 13.22 V
A8: 12.45 V
A9: 13.04 V
A11: 13.2 V
A13: 13.2 V

B1: surges from 0 to 13.98 V with gas pedal
B3: 7.36 V instead of 10.67 V measured yesterday with engine not running

Ground at A3 and A12 very good.

What do the numbers mean?

 

Thanks for reading, although no reply. My next shot in the dark is looking for another cluster.

Take care!

 

Where are the needle gages (speedo, tach) on the wiring diagram? Strange that both would go out.

 

It would be useless to try another cluster. This morning I could see that the instrument cluster was working and in perfect condition during the 30 min ride to work, all gauges were fine for speed, rmp, ECT and fuel level. Parked the car, turned engine off and retry ... no needles moving.

So it must be a loose contact somewhere, pulled out the cluster but did not disconnect the connectors, wiggled, wiggled, wiggled all reachable cables in the cavity behind the steering wheel, nothing changes.

That is very frustrating since I don't know where to look for this elusive failure. I'd rather have a defective part than that.

 

I have the exact same problem for two days now. Started while driving during fairly heavy rain fall. The gauges work when the car parked for a while, but just a few minutes between turning on and off leads to the above problem.

Have not had time to trouble shoot, but will look for some moisture, seal, ...

texholdem, did you have any success?

 

The IC had been my headdache for almost 3 weeks. Unfortunately each attempt to fix was in vain, my final solution was to replace it with another used one.

 

There are places that will rebuild yours and if I remember, for about $295. However I read recently that someone bought a used one for only $75! His only complaint was that the mileage readout was wrong. I think a dealer will re-program those pretty inexpensively but you probably have to prove what your original mileage was.

 

same problem here bud, looks like you went through a hella researh to solve the problem with no luck, sorry i cant help however i will lurk around and hopefully find a fix

PS gotta say the guys at LEXUS forums are alot more help

 

My E300D is doing the same thing. No gauges and then they will work. I have not replaced the BLS yet but that is next. The Temp neddle bounces at the bottom of its display when this problem is showing its ugly head. I would appreciate any help if anyone has seen a fix for this.

 

I was wondering if there was ever a resolution on this as I have the same problem. Everything on instrument cluster works fine, EXCEPT the dial gauges (RPM, Speed, Temp, fuel) don't move except about every 1 in 20-30 starts. When they work, they work until the engine is shut off, no matter how long or short the engine run is, if they start working they don't stop.
I'm new here, so any help or redirect will be appreciated.

 

i just had the same problem with a e420 the gauges as well as the electronics were not working.....i checked the fuses under the hood and fuse number 4 which is a 10amp fuse was blown once i changed that everything started working and havent had any more problems....hope this helps

 

Your connectors in the wiring diagram are referred to by numbers 1 for the right one and 2 for the left one, those are the big rectangles with a number(1 or 2) at the left bottom corner, then inside is a smaller rectangle with a letter at the left bottom corner for example in the first wiring diagram the wire 15g in the cluster is 1A9(or A9 in the right connector) is a red and black wire with a 0.5mm wire diameter is connected to the fuse #7 with 15A rating.

Now the bad news is that in our cars the needles aren't controlled directly by any wires, instead they get signal via CAN bus from the Engine and Traction control computers as well as other modules and sensors.

You appear to have battery voltage at the pins which correspond to the fuses, also the bulbs work just fine, which leads me to believe that you have power and ground coming to your cluster, and since you replaced it i's not the cluster itself either, so it has something to do with the Engine or other control modules.

I would suggest that you have your car scanned by a reputable indi shop or the dealer, you need to pull the codes from instrument cluster and other modules(you need to connect to the underhood diagnostic socket, not the one below the dash). Hopefully you'll have some codes which will point you in the proper direction.

Good luck.

 

Thanks for the reply. Afraid it's not my fuse for me, I checked those first. Everything on the instrument panel works just fine except those 4 dial gauges.

 

My pretty good MB mechanic has already looked at it, and says it needs a new IC replacement. I'll ask him if he did the under the hood diagnostic connection. I did find a u-tube video where a guy pulled out the control board and resodered a couple of $2 capacitors to fix his problem. Trying to figure out if I'm brave enough to try that when I get some time. Thanks.

 

Can you post the link to the video?

 

My 97 E300D has the same frustrating problem. gauges worked, then they worked sometimes, then they quit working altogether. Question: what is an "IC" that the person soldered a couple of new capacitors on? Not up on the lingo or abreviations...
The K40 board looks like it was replaced, no issues inside, the main computer board looks clean and no smoked parts or bad connections. Don't know were to go next... if it is the CAN computer, that could be an issue, probably comming from the main computer board??????

 

IC is simply Instrument Cluster

 

Thanks, should have figured out that one... that will be my next challenge... but if the previous poster is haveing the same problem and replaced the IC, and the problem persisted, then it must be elsewhere?????

 

If any of you Were in Orlando I could help...

Ckonstantin is correct. Code readers that connect to the OBDII port will not read the codes for IC.

Good luck.

 

Dis any of you get this issue resolved? My car is doing the exact same issue now