Thermal Transmitter or Coolant Temperature sender

[Phifross]

I have a Pathfinder R50 3.5V6 from 2004,

My coolant temperature gauge is not working anymore, the needle stay way down.
I have read that there are two Temperature sensor.

The Temperature sensor that is at the back of the engine which sends the coolant temp info to the ECM, but this is not the one I'm looking for.

I'm looking for the coolant temp sender, which sends the temperature signal to your dash gauge. Some call it also the Thermal Transmitter.

Can someone tell me, or send me a picture of the location of the Coolant Temperature Sender ot Thermal Transmitter please ?
I was not able to find it until now.

Thank you so much !!!!

[VStar650CL]

The VG30's had two senders, your VQ35 only has one. The ECM monitors it and sends the data to the cluster via CAN. Scan the ECM. If the scan shows a normal temperature reading then the cluster is bad, if it shows an abnormal reading then the sender is bad.

[mdmellott]

I'm looking for the coolant temp sender, which sends the temperature signal to your dash gauge. Some call it also the Thermal Transmitter.

Yeah. This one had me a bit turned around awhile back. The Nissan factory service manual refers to it as a thermal transmitter, but I found nothing in Nissan's FSM that showed me where it was located or how to check it and the instrument panel gauge. The FSM speaks to the functional check of the ECT sensor and has a rough indication that it is located at the center of the engine and below the intake plenums. My Haynes repair manual details the check and replacement of the coolant temperature sending unit (aka thermal transmitter) but has nothing about the ECT. Between the two manuals, I have sort of a complete picture now. Neither one of these sensors is easy to get at.

The temperature sending unit is located low, at the rear of the engine, on a water pipe. The picture below is from my Haynes manual. I also posted a picture of the check and replacement instructions so that you can determine if it is the gauge or the sensor that has gone bad. The other two pictures are the two temperature sensors. The ECT sensor is 25080-89907 and the one that controls the instrument panel gauge is 22630-ED000.

[VStar650CL]

That shouldn't apply to an '04, Md. Check out EL 130~132. No sender wire into the cluster, only CAN.
https://www.nicoclub.com/service-manual ... 4%2Fel.pdf

[mdmellott]

Sure enough. Looks like CAN Bus was introduced with the Pathfinder starting in 2003. It's odd that Nissan Parts Deal indicates both of those temp sensors as valid parts for the 2004, with diagrams to boot, but this wouldn't be the first time I found conflicting info between the FSM, Nissan Parts Deal, and my Haynes manual. The FSM is typically correct. Not always perfect but it is more reliable.

[Phifross]

Ok also I have only one sensor.
Now at least the sensor is working in some kind of way because the fan turns on normally, I don't have any overheating problem.

Also if the problem comes from the cluster I have to follow instructions in the EL-140 to check if yes or no it comes from the cluster.

No if its not from the cluster, I imagine it only can be from the sensor isn't it?
Or would it be possible that it comes from a fuse?
If yes from which one please?

Thank you a lot for your precious help!

[mdmellott]

There is no fuse just for the temperature gauge. Your radiator fan is crankshaft driven and operates by means of a thermal clutch coupler to fully engage when the thermal clutch heats up from air passing over it. Electric fans operate by means of a coolant temperature sensor or ECM signal but that's not the case with your '04.

A generic scan tool, not a basic DTC code reader, will be able to read the engine coolant temperature sensor and show you the coolant temperature as it heats up while the engine is running. If the scan tool shows the ECT sensor reading to be normal, then the instrument panel cluster gauge is bad. If the ECT reading does not increase as the engine warms up or otherwise looks abnormal or shows no temperature reading, then the ECT sensor is bad. The scan tool will also verify the specific DTC if there is one stored in memory.

[Phifross]

As a generic scan tool, do you think the Scan gauge 3 from ScanGauge would be ok? I ordered it but have not yet received.

Thank you so much, I really appreciate your help.

[mdmellott]

As a generic scan tool, do you think the Scan gauge 3 from ScanGauge would be ok?

The ScanGauge 3 is just a fancy code reader. It looks like it may have a readout function for the coolant temperature, but this tool would not be considered a GST. It does not even have the basic diagnostic feedback for short term / long term fuel trims or oxygen / air-fuel sensors. This would not be my choice as a diagnostics tool, especially given the cost of it would have bought a fairly decent GST.

The ScanGauge 3 is more of an accessory gauge option to mount on your dashboard. As far as I can tell, the only extra "gauge" readout it offers that your current instrument cluster gauges do not provide is an MPG estimate. I really don't think it's worth purchasing just for that.

[Phifross]

Which GST do you recommend ?

[mdmellott]

I purchased a Foxwell NT301 scanner a few years ago. It is a very basic GST. It cannot check transmission or braking system diagnostic codes, but it has served me well and paid for itself with my first use. There is also an upgraded version of the NT301 with a battery tester I think is a good value. The NT604 has a great price for a full function scanner that will check ABS, SRS Airbag, Transmission, and Engine codes, as well as the live data like the NT301 provides for the engine.
https://www.amazon.com/FOXWELL-NT301-Pr ... 00UJV3E12/
https://www.amazon.com/FOXWELL-NT301-Pl ... 08JGK8PPM/
https://www.amazon.com/FOXWELL-Scanner- ... 08PFJMTY3/

A GST with transmission and automatic braking systems diagnostic capabilities typically come with a significant price premium of at least $200 more than the NT301. Foxwell has some great prices on a tool you may only use once in a awhile. Professional grade makes and models, that are consistently used, can be very expensive.