Does anybody know where the coolant sensor is?

[roadrunner-r]

Pictures would help,also does anyone know what the the t-stat is?180-195??? OH ya what temp does the fan come on? I ask alot of questions

[ragingfish]

You should look into getting the service manual.

[engine1]

The top rad hose always leads to the thermostat housing. Coolant sensors are usually located near by either on the housing or on the intake manifold! And is it the sensor(send signals to the computer) or the sender (signal to the guage) you are looking for?

[stkos79]

Engine Coolant Temperature (ECT) Sensor ReplacementRemoval ProcedureImportantUse care when handling the engine coolant temperature (ECT) sensor. Damage to the ECT sensor will affect proper operation of the fuel injection system. Drain the engine coolant. Refer to Draining and Filling Cooling System in Engine Cooling. Disconnect the ECT sensor electrical connector (1) from the ECT sensor (2) located next to the upper radiator hose on the cylinder head. Remove the ECT sensor (2) from the cylinder head. Installation Procedure

[stkos79]

Cooling Fan ControlThe engine cooling fan system consists of an electric cooling fan, two fan relays and a fan resistor. The fan 1 relay controls power to the fan motor. The fan 2 relay controls the ground path of the fan motor. The gauge fuse supplies ignition voltage to the coils of both the fan 1, and the fan 2 relays. The RDI fuse supplies battery voltage to the switch side of the fan 1 relay. The PCM controls the ground for the coils of both relays. The PCM controls low and high speed fan operation by energizing and de-energizing the fan 2 relay which changes the ground path of the fan motor.During low speed operation, which is when the A/C is operating and the engine coolant temperature (ECT) is below 83°C (181°F), the PCM supplies the ground path for the fan 1 relay through the cooling fan 1 relay control circuit. This energizes the relay, closes the fan 1 relay contacts, and supplies battery voltage from the RDI fuse through the cooling fan motor supply voltage circuit to the fan motor. The ground path for the fan motor is through the closed contacts of the de-energized fan 2 relay, through the fan resistor to G103. The result is a series circuit with the fan running at low speed.During high speed operation, which is when the ECT reaches 93°C (199°F) or the A/C system pressure exceeds 1520 kPa (220 psi), the PCM supplies the ground path for the fan 1 relay through the cooling fan 1 relay control circuit. This energizes the relay, closes the fan 1 relay contacts, and supplies battery voltage from the RDI fuse through the cooling fan motor supply voltage circuit to the fan motor. The PCM also supplies the ground path for the fan 2 relay. This energizes the relay, switches the fan 2 relay contacts, and supplies a ground for the fan motor directly to G103. The result is a series circuit with the fan running at high speed.The A/C refrigerant pressure switch is in parallel with the PCM controlled ground for the coil of the fan 2 relay. If the A/C system pressure exceeds 1520 kPa (220 psi), the pressure switch closes the ground circuit to the coil of the fan 2 relay, initiating high speed fan operation.The PCM commands low speed fan operation when all of the following conditions occur:The A/C system is operating. The A/C system pressure is below 1226 kPa (178 psi). The engine coolant temperature (ECT) is below 83°C (181°F). The PCM commands high speed fan operation when either of the following conditions occur:The ECT reaches 93°C (199°F). The A/C system pressure exceeds 1520 kPa (220 psi).

[roadrunner-r]

Where did you get all this information?I want my fans to turn on sooner,I was talking to Transtior(matrixowners.com)He said i need to put a restior on the coolant sensor to tell the ecu the motor cooler,and get the fans to come on sooner. To get more timing! I havnt been able to get ahold of him anymore. He told me i need a 540 restior. I want to know what does this tell the ecu the temp is?he also told me about turning the fans on sooner. I dont understand what he means. (His directions) He told me if i had a CAI there's a ~blue~ wire that was left out after installing a CAI. I dont have a CAI.Does anybody know what wire he is talking about?Is there any other way to turn the the fan on without setting the SES light?One more thing is the coolant sensor a two wire sensor or one? Because i think i founf it and it only has one wire. IT sits on top of the t-stat. I think thats it.I need a manual,can someone scan it??

[joatmon]

you beat me. My answer would have been The thermostat begins to open at 179F (82C) and is fully open at 203F (95C) The thermostat housing is where the radiator hose attaches to the cylinder block on the belt side of the engine.The computer turns the cooling fan on low speed when the AC is on and the engine temp is 199F (93C) or the AC pressure is high enough (> 220psa/1520kPa)There is one sensor, which feeds the computer. The computer then drives the temp gauge. The sensor is located between where the upper radiator hose and a heater hose attach to the cylinder head. (on the driver's side of the engine)I don't know what putting a resistor on the temp sensor would do, except trick the computer to think that it was a diferent temp that it really was. Did the matrix guy say to put the resitor in series or parallel with the sensor? Will make a difference on whether to trick the computer to thinking the engine is hotter or cooler than it really is. A side effect will be to change when the cooling fan comes on, not sure what it will do to your timing/performance once you get the engine up to temp. What's an SES light? There's also timing resistors for sale on ebay, but I wouldn't put them on my car. quote:You should look into getting the service manual.

[ragingfish]

quote:What's an SES light?Service Engine Soon

[roadrunner-r]

Thats what iam trying to figure out. How to wire it. He told me that restior is telling the ecu the car is cool to add timing and fuel,and thats why i need the fans to turn on soonerSES = Service engine soon,same thing as CEL

[ragingfish]

I think you're backwards.If the car is cool, why would the fans turn on?You want to tell the car the engine is hot...That aside, though, I personally wouldn't recommend messing with the ECU like that...go with a more reliable HP increase, such as CAI or supercharger...

[scherry2]

I wouldn't waste my time doing what you are doing. you want more HP save your $ and get a CAI.

[joatmon]

quote:I wouldn't waste my time doing what you are doing. you want more HP save your $ and get a CAI. he's already got a custom ram air intake, so probably not interested in a CAI. ------------------------------------------------------------I don't have a clue what the effect would be of tricking the puter to think the engine is at a different temp, what that would do to performance, engine wear, etc.

[roadrunner-r]

ragingfish,I wan the temp to stay low get it. The cooler the more Hp its gonna make,and yes i have a custom CAI.

[philndz]

If you pull this off then I would love to copy it....get pics (if possible) when you hook it all up. I was wondering if I could wire in a switch to turn on the fans when I want to yet still let them run by the ECU for the rest of the time. An "Over-ride ON" switch.Keep us posted!-Phil

[ragingfish]

quote:ragingfish,I wan the temp to stay low get it. The cooler the more Hp its gonna make,and yes i have a custom CAI.Ok, I follow you now.

[Hot Vibe]

Since you live in Texas you can just have the fans run all of the time. You do not live in a cold climate area. Does it get below 20F in Texas?I recommend not to *******ise your colling system. Messing with thermostats and PCM's and ECU's are a very bad idea. Yes it may work for a while but it is the burning the candle at both ends theory. Once you break the seal on those items you could be screwed. If you make mistakes the dealership will probably not help you. At this time I would usually provide a schematics diagram showing parts diagram assemblies but it would be against my better judgement. They are intended as engineering diagrams. I can not tell you what to do but if you want another expert opinion besides mine then go to a dealership and ask from a service standpoint where these things are and what they do. This mod is not for the novice. You can really screw up your car by doing this. When it comes to the PCM the Matrix and the Vibe are 2 different vehicles. Anyone who tells you differently did not design it.

[roadrunner-r]

I would likek to have a switch to turn it on and off. I did this on my oo GTP,ran the fans with a switch.A diagram would help.

[joatmon]

I kind of understand the concept of cooler air being denser giving more power to the individual ingition blasts, that's one reason why a CAI helps, but how does having the entire engine cooler give you more power? Is it to just reduce intake mix heating?

[MadBill]

That's the theory, joatmon: Lower engine temperature means cooler intake ports and valves, thus cooler, denser charge and more power. The problem is that within limits, combustion efficiency and friction are improved by higher engine temperatures, so it's a trade off (also overall, emissions are improved by higher engine temperature, so most cars run ~ 195 F. thermostat stock.) Obviously if you put in say a 170 degree thermostat, but the fan comes on at 200, you'll end up in warm/hot weather at 200, regardless of the thermostat setting, hence the desire to mess with the "fan on" settings.Additional complications arise when you try to trick the ECU with bogus numbers. The theory here is that if you convince it that the engine is running colder, it will supply more spark and fuel, hopefully improving power (but who knows, unless they have done a ton of tests on your particular make/model/year?)Bottom line, I'm with Hot Vibe: Mucho bad idea unless you really know what you are doing!(A simple fan overide switch, provided the chosen wiring schematic, use of relays, etc. is electrically sound, shouldn't be too problematic, but GM does hot weather testing in Death Valley, so how much more is really needed?).

[joatmon]

Thanks, trying to get the concepts down. Since I bought a vibe for combination of space and fuel efficiency (I know, how boring ) I'm not interested in doing this mod.

[Hot Vibe]

I will rephrase my first remarks. This modification is useless and could damage the electronics of this system. You would get faster times if you were to remove the antenna. You engine runs at that temp for a reason.