Coolant wiring I just replaced the coolant sensor on my 98 pontiac sunfire. The temperature gage still doesn't work so we retested the code to make sure that it said the coolant sensor and it did. So we took out the sensor and had it checked and it is fine. I'm wondering where I can get wire for coolant sensor and how hard it is to install in the car as we figure it's a a short in the wire. Our next step is to take it to the dealer if we can't fix it with replacing the wire. Thanks

Are any DTC'S - diagnostic trouble code's stored in any module ? BCM - body control module , PCM - engine computer ,IPC etc.... It's the temp. gauge not thermostate gauge Did it work after replacing the thermostate an coolant temp sensor ?
Engine Coolant Temperature Gage
The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the engine control module (ECM). The IPC receives a serial data message from the ECM indicating the engine coolant temperature. The engine coolant temperature gage defaults to 38°C (100°F) if:
• The ECM detects a malfunction in the engine coolant temperature sensor circuit.
• The IPC detects a loss of serial data communications from the BCM.

The first thing too do would be to hook up a factory or some other type of professional scan tool an see what the temp. sensor is telling the engine computer an if the BCM is showing the same temp. data . And is that info. getting to the instrument cluster . Knowledge of how it all works an proper diagnostic technique is the key to finding the problem .
If the IPC is see same temp the engine computer is an the gauge isn't working something is wrong with the gauge itself. New instrument cluster would be needed .

First off you would need to know from where an how this data get's to the instrument cluster , Computers involved ( control module's ) etc... serial data network - how the computers (modules ) communicate . Special tool's involved in testing this data - factory or professional scan tool - to view data from sensor's - temp sensor , fuel level sending unit in the fuel tank . Both of the these sensors are input's to the PCM/ECM - engine computer , which shares this info to other module's which need this info. The GMLAN serial data network is the data network which does this .
The instrument cluster has a microprocessor inside which view's this data an controls stepper motors to drive the gauge need .
Not working correctly or not at all can becaused by any number of thing's . The instrument cluster could have DTC'S - diagnostic trouble code's stored . Auto part stores can not read these code's or BCM code's . .
Engine Coolant Temperature Gage
The engine control module (ECM) calculates the engine coolant temperature as determined by the coolant temperature sensor. The ECM sends the engine coolant temperature to the body control module (BCM) via the serial data circuit. The instrument panel cluster (IPC) displays the engine coolant temperature when the BCM sends a serial data message to the IPC indicating the engine coolant temperature. The engine coolant temperature gage defaults to 0° or below if:
• The ECM detects a malfunction in the engine coolant temperature sensor circuit.
• The IPC detects a loss of serial data communications with the BCM.
• The BCM detects a loss of serial data communications with the ECM.
Fuel Gage
The engine control module (ECM) sends the fuel level percent to the BCM via the serial data circuit. The IPC displays the fuel level as received from the BCM. The fuel gage defaults to E (empty) if:
• The ECM detects a malfunction in the fuel level sensor circuit.
• The IPC detects a loss of serial data communications with the BCM.
• The BCM detects a loss of serial data communications with the ECM.
When the fuel level is less than a pre-determined value, the Low Fuel indicator message illuminates.

Your best bet , take your vehicle to a qualified repair shop.

What diognostics say its a sensor ?????? No diagnostic's ever tell's you it's a sensor . You as a technician would need to prove that by testing electrical circuits , viewing coolant temp sensor . Hooking scan tool and trying to command the gauge with by directional control . The temp gauge not showing any temp. ? No movement ? Engine Coolant Temperature Gage Inaccurate or InoperativeStep Action
Yes
No
Schematic Reference: Instrument Cluster Schematics
1
Did you perform the Instrument Cluster Diagnostic System Check?
Go to Step 2
Go to Diagnostic System Check - Instrument Cluster
2
Install a scan tool.
Turn the ignition ON, with the engine OFF.
With the scan tool, perform the Lamp and Gauge Check in the IPC Special Functions list.
Does the engine coolant temperature gage move up and down when commanded?
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
Go to Step 3
3
Replace the IPC. Refer to Instrument Cluster Replacement .
Did you complete the replacement?
Go to Step 4
--
4
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 2
Would hate for you to replace the coolant temp sensor an find out that's not the problem ! Does the vehicle start an run good ,trans mission shift good ? If so it's not the coolant temp sensor .
Engine Coolant Temperature Gage
The ECM sends coolant temperature as determined by the coolant temperature sensor to the BCM via CAN serial data. The IPC displays the engine coolant temperature with the gage when the BCM sends a class 2 message to the IPC indicating coolant temperature percentage. The engine coolant temperature gage defaults to cold (0°) or below if:
• The ECM detects a malfunction in the engine coolant temperature sensor circuit.
• The IPC detects a loss of class 2 communications with the BCM.
• The BCM detects a loss of CAN communications with the ECM.

Check engine light on ? The coolant temp sensor is a input to the PCM - engine computer ! All wires come from an go to the PCM . What type of problem are you having ? Maybe able to save you some aggravation an time chasing gremlins . Coolant gauge not working ?
Engine Coolant Temperature Gage
The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the powertrain control module (PCM) or the engine control module (ECM). The IPC receives a serial data message from the PCM/ECM indicating the engine coolant temperature. The engine coolant temperature gage defaults to 100°F (38°C) if there is a malfunction in the engine coolant temperature sensor or the IPC detects a loss of serial data communication with the PCM/ECM.

But if you insist ,you can find free wiring diagram's here http://www.bbbind.com/free_tsb.html Enter vehicle info. year , make , model an engine ! Under system click on engine ,then under subsystem click on fuel controls . Click the search button then the blue link. The second an third diagrams both show coolant temp sensors . Both go to the PCM .

code p 0480 refers to engine coolant blower motor 1 ---circuit malfunction=== causes ---wiring ---engine coolant blower motor ---ECM
code p 0116 refers to engine coolant temperature (ECT) sensor ---range b/performance problem ====causes coolant thermostat---poor connections---wiring---ECT sensor

Some older models of cars had a coolant temperature switch; a two-wire device that was used to cycle the cooling fan, and an engine temperature sensor that was used by the ECM as part of the engine control loop. Newer cars (this one included) use the coolant temperature sensor for both purposes. There is only the one sensor serving both purposes.

Sounds like your cooling fans on the radiator are not working. The fans are activated by a thermol switch on the engine or radiator reading the coolant temperature and an A/C switch. When the coolant is too hot the fans should activate cooling the system down. And, when the A/C is on the fans should also activate in order to cool the condensate so the A/C would work.

When you are driving, the movement of the vehicle throught he air is providing enough air flow to keep things cool and functional.

I would check the radiator fan fuse or fuses first. If those are OK I would try to run the fans with 12 volts and a ground that I supply just to see if the fan motor(s) actually run when powered. If the fan don't run when powered then the fans are bad and will need to be replaced. If the fans do run when you power them manually, then something is not allowing the power to activate, like a relay, control unit, or wiring.

It will take a little diagnostics, but it is not too difficult to chase it down.

CHECK YOUR COOLANT LEVEL THERE IS A SENSOR THAT SENDS A TROUBLE CODE WHEN IT GETS BELOW A CERTAIN LEVEL.

The sensor is threaded into the pipe shown below. Please let us know if you have more questions.

2.2L Engine

NOTE Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

1. Turn OFF the ignition.
2. Drain the coolant system.
3. Disconnect the Engine Coolant Temperature (ECT) sensor electrical connector.
4. Carefully back out the ECT sensor.

Fig. Coolant temperature sensor for the 2.2L Engine

To install:

1. Coat the threads only with sealer P/N 9985253 or an equivalent.
   NOTE Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
   
2. Install the ECT sensor and tighten the ECT sensor to 18.5 ft. lbs. (25 Nm).
3. Connect the ECT sensor electrical connector.
4. Refill the engine coolant system.

sending unit or float in gas tank, check if any broken wires or well plugged in and then check the float for the gas.