# '00 Sentra SE: infrequent tach/speedo/temp gauge failure



## ahains (Mar 14, 2004)

Hi all,
My wife bought her 2000 SE new, and it is still covered by the extended factory warranty she opted for.

We have an intermittent issue where the tachometer, speedometer, and temperature gauges will all suddenly lose power and fall to their off positions. When this happens the cruise control also kicks off (and cannot be turned back on), presumably because it won't operate without the speedo signal.

This usually happens after about 45 minutes of uneventful driving on the freeway. Sometimes it happens on the way home from the in-laws, which would put it at about 25 minutes into the drive. I don't think it has ever happened within the first part of a drive.

It is not dependent on cold/hot/dry/wet weather.

I just made an appointment to take it in to the dealer on Thursday morning, but I have a bad feeling about it. I inquired about diagnostic fees, and they reported that I would be charged $79/hour if they could not find the problem, or if they found a non-warrantied part to be the culprit. From how infrequently it happens, and I cannot reproduce the problem on demand, I do not see how they could possibly isolate the problem.

It sounds to me to be an electrical connection that is physically flaky. Or possibly one that is an issue the engine reaches full temp, but I think this is less likely. I could test this by making a spirited run up I-90 to Snoqualmie pass (by my house), but the fact that it sometimes happens after very flat and easy freeway driving suggests it is not heat.

I am posting in hopes that someone with knowledge of the electrical system of this car can suggest where I could find any electrical connectors that would encompass the power or signal for all 3 of these gauges. Maybe it is just a loose ground in the wiring gauge cluster? I'm moderately comfortable with working on cars, and with electronics, but tearing apart a dash scares the heck out of me 
Any tips on how I would go about finding the nuts and screws to remove to get into the gauge cluster? I haven't tried yet, so I apologize if it is simple and I should have simply looked 

Also, anyone else had the same problem? I couldn't find anything remotely related through the search function or with google.

Thanks!
-Adrian


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## chimmike (Oct 17, 2002)

I agree with your suspicion that there's a bad electrical connection somewhere.

Don't waste the money on having them do a diagnostic...all they do is plug in the damn consult computer..........have them check all the connections in the dash behind the gauge cluster.


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## ahains (Mar 14, 2004)

Ok well 1.5 years later, I decided to try and track this down 
I took off far more dash components then necessary and eventually got the gauge cluster out.
If anyone else is wondering - all you really have to do is remove the screws for the plastic housing of the steering wheel column, remove the top and bottom pieces of it, and then remove the two screws above the gauge cluster and pull it out.

Now that I have the back of the gauge cluster accessible, I see there are two big wiring plugs that go into the back of it. They both felt snugly inserted, so I don't think either of them were the bad connection. They have a tab you push in to release them, but it wasn't super easy to get them out so I gave up (I didn't want to take them apart right now anyway, so getting them out wasn't a high priority).

The other end of the clusters of wires go into a big fat cluster of wires and off into no-man's land. So verifying the connection at the other end (at least without a wiring diagram) looks excessively difficult.

I'm left with the following possible avenues to pursue:
1)Pull the gauge cluster, open it up, and look for any global grounding or power points that may have a problematic connection. I don't have a wiring diagram (anyone wanna PM one to me? ), so I'm pessimistic about this improving the situation.
2)Go with the assumption that the gauge cluster is at fault, and just try to swap in another one (ebay or junkyard)
3)Locate a wiring diagram, solder some wires to the + and - supplies for the gauge, drive around for hours/days until I can reproduce the problem, and verify if lack of power is the issue. If so, then troubleshoot wiring from there.

Regarding #2, I'm hoping someone may be able to answer a few questions:
-Can I expect any B15 cluster to swap right in, or does it have to be like 2000-2002? Have to be an SE like mine?
-Do you know if the odometer goes with the gauge cluster or if it is stored elsewhere in the car (e.g. ECU)?

Blech. Help?


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## SENTRASER (Jan 6, 2005)

Try these things, they're from ALLDATA. My guess is your cluster needs replaced.



DIAGNOSIS FUNCTION 


Odo/trip meter segment can be checked in diagnosis mode. 
Meters/gauges can be checked in diagnosis mode.
HOW TO ALTERNATE DIAGNOSIS MODE 



Turn ignition switch to ON and change odo/trip meter to "TRIP A" or "TRIP B". 
Turn ignition switch to OFF . 
Turn ignition switch to ON when pushing odo/trip meter switch. 
Release odo/trip meter switch 1 second after ignition switch is turned ON . 
Push odo/trip meter switch three times within 7 seconds .








All odo/trip meter segments should be turned on. NOTE: If some segments are not turned on, unified meter control unit with odo/trip meter should be replaced. At this point, the unified control meter is turned to diagnosis mode.








Push odo/trip meter switch. Indication of each meter/gauge should be as shown in figure during pushing odo/trip meter switch if it is not malfunctioning. NOTE: It takes a few seconds for indication of fuel gauge and water temperature gauge to become stable. 
Turn ignition switch to OFF or start engine to cancel diagnosis mode.


PRELIMINARY CHECK 










Symptom Chart 1 (Malfunction is Indicated in Diagnosis Mode) 









Symptom Chart 2 (No Malfunction is Indicated in Diagnosis Mode) 









Power Supply Circuit Check 










If NG, check the following.


10 A fuse [No.12, located in fuse block (J/B)] 
10 A fuse [No.30, located in fuse block (J/B)] 
Harness for open or short between fuse and combination meter

GROUND CHECK


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## SENTRASER (Jan 6, 2005)

A couple wiring diagrams too:


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## ahains (Mar 14, 2004)

Thank you very much for that info, that is very useful!
Given that the issue is so intermittent it makes it very difficult to troubleshoot.
When it has happened before turning the car off and on has made no change, so this is great that I can try the gauge diagnostic mode if it happens again.

Since the cruise control disengages during the period of gauge failure it makes me lean towards the speed sensor mentioned in symptom chart 2. If I can find this I would like to see if disconnecting it causes the same complete gauge cluster failure or if it only affects speedometer & cruise. This would help me narrow it down as well.

I recall on a different car the speed sensor was screwed into the tranny with a knurled nut.. but it was also a manual transmission. Do you know if it is the same on the Sentra? I'll have to look and see if I see anything obvious.


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## SENTRASER (Jan 6, 2005)

ahains said:


> Thank you very much for that info, that is very useful!
> Given that the issue is so intermittent it makes it very difficult to troubleshoot.
> When it has happened before turning the car off and on has made no change, so this is great that I can try the gauge diagnostic mode if it happens again.
> 
> ...


The speed sensor is an electrical unit on the post B13 cars, which is located on top of the tranny towards the firewall, as it runs off of the differential. My guess is that your gauge cluster is the culpret, the nissan dealer telling you that if they dont find anything wrong sounds like a ploy to get you not to have them look at it, because if it's doing sometihng wrong it shuold be covered under waranty no matter what.

I'd say its the whole gauge unit.


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## SENTRASER (Jan 6, 2005)




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## ahains (Mar 14, 2004)

I called the parts guys and they didn't really have any idea what a "unified meter control unit" was. They did say they showed a circuit board for the gauges, so I can't see how this could be wrong 
It's unfortunately $350 or so, but that is ok if it fixes the problem.
I'll pull the old one (hopefully tonight) and look it over, if I'm super lucky maybe there will be an obvious poor connection or something


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## ahains (Mar 14, 2004)

Ok got the gauge cluster pulled out. I looked over the circuit board and the solder connections and it all looks pretty good. One conductive path near one of the connectors kind my eye as looking a tad suspect, but it looks like it is probably just flux from the look of the flux on all of the other solder connections around the connector. I can't really imagine it actually being a faulty electrical connection, but who knows 

I'm wondering - is the gauge controller circuitry stuff known to be problematic in this car? If not I may be tempted to try a used cluster if it can be had for far cheaper (although the yards around me always seem to be kind of crazy expensive )

After reading through all of that info again, one important question jumps out at me - do the warning lights go on if I turn the car off and on when the problem is appearing. Neither my wife or I can recall. It sounds like if they are also failing then it would be more a power than a circuit issue.

It shows some pins to test to verify the power supply in M30. Maybe I am being dense, but I don't have the faintest clue where this M30 connector is. Any pointers?

Thanks so much for the help!


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## SENTRASER (Jan 6, 2005)

No problem, just hope I'm helpin! How cool am I?? Like this pic?:fluffy:


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## ahains (Mar 14, 2004)

Oh, M30 is one of the connectors! I see..
You're way cool 

Hmm. That seems kind of tricky to hook a voltmeter up to while the cable is plugged into it.
I guess I could solder a tap wire onto the pin of the socket, and run this out into the driver area so I could test the voltage. Seems kind of weird though. I assume that is not what a Nissan tech would do. 
Actually I should take a look at the back of the male portion of the socket, maybe you can just slide some thin wire into the wire compartments? Might work..

In any case since I have the cluster out and the circuitry appears to be the culprit I think I'll replace that first. I'll test out the power somehow if that doesn't fix it.


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## SENTRASER (Jan 6, 2005)

ahains said:


> Oh, M30 is one of the connectors! I see..
> You're way cool
> 
> Hmm. That seems kind of tricky to hook a voltmeter up to while the cable is plugged into it.
> ...


You just test those pins for power with it unpluged and ignition on, no need to sneek in the back.


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## mazinger4 (Nov 27, 2008)

*Did you ever fix the problem*

I have a 03 where all the gages went out at the same time. Was wandering what did you do to fix the problem?:nerd:


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## rvv (May 25, 2015)

*I have same problem*

I have a sentra 2003. My problem start two weeks ago. The odometer-trip display start to on and off all segments of display in a crazy way. Pushing the trip/reset button sometimes fix, sometimes not.

Days after that, the gauges of fuel, temp, speed and tacometer going off while driving. Sometimes, with a strong hit at board the gauges wake up.

Now, all the mention problems are more frequently. From Three days ago, at night with lights on, the board not have lights. 

I pulled out the unified board, check the connectors, all seems ok. I only found a lamp board damaged, for that reason the board are in darkness at night. But about the other problems, i do not have idea about the cause. 

Indeed, while I was inspectig the unified unit board the needles of fuel and temp gauges felt down, I put in places again. But when I install the unified board again, the gauges of fuel and temp indicate wrong mettering.

Same questions, for the 2006 and jan of 2015 persons. Could you fix your problesms ??


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