DennisMik

iTrader: (2)

That is to calibrate the sending unit to send the proper voltage to the dash gauge. The little printed circuit board is a variable resistor. When the float arm is in a certain position, the resistance reading should be a certain value. Moving the little arm will move the printed circuit board to achieve that resistance value.

Page EL-80 in the FSM shows the procedure.

If you get any warning lights in the cluster, such as the self test before starting the car, 12 volts is getting to the cluster. The ON position of the ignition key sends 12 volts to pin 37 of the instrument cluster through fuse # 13. The instrument cluster printed circuit board then distributes the 12 volts to whatever part/piece needs 12 volts. Unless the printed circuit board has a crack in it that would prevent 12 volts from getting to the SES lamp.

To that extent you would have to have several instrument clusters with a cracked printed circuit board. But you might as well check for 12 volts at the SES lamp socket. Lay a towel on top of the steering column and take the cluster out and lay it on top of the steering column, face down, leaving the wire harness connectors connected. The towel is so you don't scratch the plastic face of the cluster. Remove the SES lamp and holder. Turn the ignition key to the ON position and check for 12 volts around the hole where the SES lamp would plug in. If you are brave, and assuming you have found 12 volts, put the bulb back in and using a jumper wire that is connected to ground, touch the other contact for the SES lamp and see if it will light.

I am not aware of any fuse in the steering column. Unless the air bag has one. I would be interested in seeing about that. Could you tell me the page number? But the wiring for the SES lamp does not go through the steering column, so I doubt a fuse there would be part of the instrument cluster circuitry.

You're welcome.

95Maxi

iTrader: (40)

Ok, tested 12v is present fuse is fine, continuity from cluster to ecu pin 18. Tried unplugging again tonight the ecu using a jumper from pin 18 to ground no light tried changing or swapping working bulbs in the cluster .. am I using the wrong bulb? Is there a specific bulb number? Trace on the cluster are all good on all 4 clusters 2 of which burnt the trace for the fuel but not for the ses light so none of the 4 clusters have burned out traces for the ses light... this is really leaving me speechless... maybe the fuse panel something happened internally? Can those be replaced? Idk but I cant give up until I find this issue ...
I have been researching up and down .. whats next ? Oh btw I didnt do it today but I have jumped the ses light before got it to come on but it stays on no matter what I do ..

at least I figured out the fuel light issue so far .. the sending units are all bad I guess 1 sending unit worked when I first bought the car than never did 2nd was toast and keeps the light on all the time the 3rd semi worked yesterday but had an issue starting the car so thats a no brainer so I have the one that keeps the light on till I buy a brand new oem one...

DennisMik

iTrader: (2)

Yes there is a specific bulb and it is chosen to give a certain brightness and of course work at the voltage the car uses. If you got a bulb that required a higher voltage than the 12-14 volts the Max uses, it would be dim to not lighting, depending on the voltage it was designed to use. If it was designed for a lower voltage, say 6 volts, it would pop like a flash bulb.

But if you have used a bulb and holder from one of the other warning lights (and you are sure that one is working) then MAYBE the new bulb and holder are OK. Personally I would permanently swap the SES lamp and holder with one of the other lamps, like maybe the seat belt lamp, and get rid of the nagging question of "is this the correct light bulb?".

So this morning during a lull in the rain, I went out to my car. I took the connector off of the ECU, turned the ignition switch to "ON" and and grounded pin 18. The SES light illuminated. My car is a 97, but if you are willing to believe the Nissan wiring diagrams, the 97 and 99 are the same for this.

So we are back to the "everything tests OK, but it doesn't work." Something has been overlooked or missed. I don't know what it is, though. What I suspect is that how I would do something and then tell you what and how to do it is somehow different than what you end up doing.

Admittedly I am running out of ideas. But here is another idea. Again, take the instrument cluster out and lay it face down on the steering column. Don't forget the towel. With the wire harness connectors still attached, turn the ignition switch on and ground pin 38 in connector M84, the one behind the temperature gauge. See FSM section EL, page 71 for the pin arrangement or page 82, bottom. Grounding this pin should make the SES lamp light up.

If the lamp lights up, then there are questions about the wire continuity back to the ECU or if you grounded the correct pin (pin 18) back at the ECU.

Patience and step by step is all I can tell you.

95Maxi

iTrader: (40)

So, I grounded the pin 38 and have light...eureka. . What does this mean?

95Maxi

iTrader: (40)

While we are at it quick question checked my obd2 and came up with all these pending codes

DennisMik

iTrader: (2)

One of 2 things:

1) It means that the wire for the SES light that goes from the connector on the instrument cluster to the ECU pin 18 does not have continuity. When testing stuff, when you grounded pin 18 at the ECU and the SES light did not come on. This meant several possible problems, but now that you just grounded pin 38 at the cluster and got the light, this implies the wire between the cluster and ECU is bad (open), even though you did a continuity check of the wire and said it was OK.

2) It means the ECU is bad. You did a continuity check of the wire between the instrument cluster wire and the ECU and said it was good. So that means the ECU is not putting a ground out on pin 18 of its connector. But yet, when you grounded pin 18, the light did not come on

These 2 points are in complete disagreement with each other. You need to re-do the pin 18 grounding AND the wire continuity test. They both cannot be true.

95Maxi

iTrader: (40)

If I redo the test and get ground from pin 18 to turn the light on what does that mean the ecu is bad ? What can I do now ?

DennisMik

iTrader: (2)

I don't have the time right now to get into these codes, but here is a brief (real brief) description and where in the Nissan FSM to read up on it.

P0446 EVAP Canister Vent Control Valve. Page EC-354.

P1105 MAP/BARO switch solenoid valve. MAP/BARO means Manifold Absolute Pressure/Barometric Pressure. Page EC-386

p1490 Vacuum cut bypass valve. Page EC-483

You know what the P0180 is, so I will not address it unless you have questions.

Later this evening I can spend some time on this.

DennisMik

iTrader: (2)

If you ground pin 18 and the SES light lights, then the ECU has a problem. Not sure what you mean by "What can I do now?"

Gotta run.

95Maxi

iTrader: (40)

OK RE-TESTED- From the ecu harness pin 18 to ground light turns on . from pin 38 cluster side to ground light turns on .

unplugged the harness from the cluster which holds pin 38 and unplugged the ecu harness which holds pin 18. so the harnesses are disconnected from the cluster and the ecu .. ran continuity and it was there loud and clear but no light.

DennisMik

iTrader: (2)

When you ground pin 18 in the ECU connector and the light turns on, you have continuity in the wire. Checking the continuity of the wire just confirm this. It looks like the ECU is the reason the SES lamp does not light up.

As for the CEL codes, other than the P0180, they are all part of the pollution controls.

The P0446 is a solenoid operated valve bolted onto the charcoal EVAP canister behind the driver rear wheel. This valve has a plunger inside that gets corroded and will not move. Sometimes you can remove it and spray WD40/PB Blaster/Liquid Wrench or something and get it to free up.

The P1490 is another solenoid valve a little bit forward of the EVAP canaster that isn't working. There is a drawing in the FSM on page ec-483 to show where it is at.

The P1105 is yet another solenoid operated valve that switches vacuum line connections. If you were working on the engine in the corner by the battery, you could have knocked off one of the vacuum hoses or maybe one cracked and broke off.

Here is a photo for the location of this valve.

95Maxi

iTrader: (40)

Thank you..

Do you think these pending codes have something to do with this ecu issue?

also can I use a jumper to get ground for this pin 18 issue so that the light will work properly? I doubt it but I figured id ask

95Maxi

iTrader: (40)

Ok news, I put my friends ecu in from his 99 automatic transmission and the engine light came onand the only code I had was my p0420. The car didnt start cause of the NATS I do have the key and the ignition ring for the NATS . So should I just use that one or get one from a 99 5 speed ?

DennisMik

iTrader: (2)

If you use the auto trans ECU, you'll probably get codes for auto trans stuff in the P07xx range. Don't know for certain, though. So I would suggest you get the manual trans ECU.

Codes are stored in the ECU, so the P0420 code is from your buddy's car. The engine would have to be running for the ECU to sense the voltage from the O2 sensors and decide there is a problem.