Whostheboog

Temp gauge registers fine unmoved datascan 2 showed 230°... Here's the deal. I accidentally threw the only chip key to the 5 speed away back in October so it sat. So thanks to datascan 2, a lot of research, even more trial and error, and almost giving up and sending to the dealer... I got the Gle key programmed to the 5 speed by holding the Glee's chip near the igniton while the door key which was all I had for the 5 speed started it. At first no luck with the keys on top of the antenna box but then realized the sweet spot. Well the car finally cranked and ran like a top. First time it got to run on it's non job weld vias fix, gutted, ported, and polished lim. I let her idle for quite a bit because of a hole in the tire couldn't take her for a spin. Glee is at my parents house so couldn't swap wheels. Noticed the temp gauge still reading absolutely fine in the middle. Kewl beans. Then noticedthe temp gauge on the laptop with datascan 2 because I was attempting to relearn idle which was denied due to being over operating temp... Found one article on a different site avcidentally where a fella claims there were a lot of defect reports of the 2k 2k1 temp gauges doing this. Basically they will shoot up finally at the 250° mark. There was something mentioned about 2 different temp sensors and one sucking. Some people said he was wrong but my car seems to be acting that way... Any input, suggestions, or even yays or nays if yall's have ever shown similar problems would be greatly appreciated.

DennisMik

iTrader: (2)

First off, lets start by you telling us what year the car is. The 2000 & 2001 do things one way and the 2002 & 2003 do things another way.

You state "Found one article on a different site avcidentally where a fella claims there were a lot of defect reports of the 2k 2k1 temp gauges doing this." You will find people posting stuff like this because it happened to their car. Because it happened to them, this translates into an epidemic, regardless of reality. In this case, reality says NO.

Could the gauge be bad? Of course it could. It is made by man and everything that man makes will fail eventually. It's just that some things take longer than others.

It sounds like you have a 2000 or a 2001, but that is an assumption. On these cars, there are 2 temperature sensors. One is for the gauge in the dash and the other is for the ECU. It is called the ECTS (Engine Coolant Temperature Sensor). This gauge is the one that gives you the reading on the datascan.

Based on your statement that the temperature gauge is indicating normal, I would say the ECTS is the problem. These sensors fail a lot more often than the dash gauge does.

You can do one of 2 things. You can buy a new one for $30 - $35 and see if that resolves the problem or you can test the sensor to see if it is bad.

To test the sensor, you measure the resistance with an ohmmeter. The resistance changes based on the temperature of the water. Without removing the sensor, run the engine until it is hot and turn the engine off. Unplug the wire harness connector and using the ohmmeter, measure the resistance. At 200ºF the resistance should be between 235 and 260 ohms. At 212ºF, the resistance drops to below 200 ohms and and would be even less at 250ºF. I don't have exact info for 250º.

The 2 temperature sensors are located next to each other. Follow the upper radiator hose back to where it connects to the engine. Maybe 3 inches further, you will see the 2 sensors. The first one is for the dash gauge and has one wire on it. The 2nd one is the ECTS for the ECU and has 2 wires on it.

Reference page 174 or page 191 in this link:

http://boredmder.com/FSMs/Nissan/Maxima/2001/EC.pdf

Whostheboog

I shall test it. I brought up what dude said because it was awfully coincidental. But I didn't assume another maxima conspiracy cover up as that was the only place I have read such. The connector was in bad shape and highly corroded so I started with replacing the connector from the wire to the sensor. Going to test the sensor monetarily. Resistance testing never remains in my head what number resistance test to set my meter to...