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Temperature vs. resistance values

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Can either of these codes cause my 1999 Oldsmobile bravada SUV to over heat: P0442 ornP1361 or P0117??

code p 0442 refers to EVAP system so that is unlikely
check the fan operation and if you have a viscous fan hub ( fan clutch ) replace it
if you have electric fans , check coolant temperature sensor for operation , fuses , relay and fans
overheating is from low coolant levels , head gaskets/cracked heads, blocked radiator cores , fins flaking off core tubes, incorrect timing, blocked exhaust( cat converter)problem thermostat, over loading /over speeding, overdrive not engaging
if you over heating is predominately at lights , slow moving traffic or high engine rpms with low speed --check the fan operation and if it is viscous fan hub driven --replace the hub or if electric fans have that circuit checked out

Sep 07, 2016 | 1999 Oldsmobile Bravada

1 Answer

Why doesn't my heat gauge work on my 2007 Chevy Uplander

Your coolant temperature switch is bad,here's a link on where it is,to remove,just disconnect electrical connector,get wrench and remove,might need a long sock to remove. Repair Guides Component Locations Coolant Temperature Sensor AutoZone com Here's a new part. Repair Guides Component Locations Coolant Temperature Sensor AutoZone com Get the lifetime warranty one if you can.

Jul 27, 2015 | Cars & Trucks

1 Answer

How do i replace a coolant temperature senser on a 2001 volkswagen jetta with the 2.0 liter motor?

Here's a link from Autozone's repair guide showing you how to replace your sensor,you can join Autozone's site,become a member,it's free,then you can use all of their repair guides,hope this helps. SAVE 20 ON ONLINE SHIP TO HOME ORDERS OF 100 OR MORE

Jul 08, 2015 | Volkswagen Cars & Trucks

2 Answers


The ECT (Engine Coolant Temperature) sensor is a thermal variable resistor (also known as a "thermistor"). The ECT delivers a signal to the THW terminal of the Engine Control Module (ECM) which varies with engine coolant temperature. The ECM uses this signal to control the fuel injection system, the overdrive operation on vehicles equipped with electronically controlled overdrive transmissions, spark timing control, idle speed control, fuel pressure control system (if equipped), heated oxygen sensor system (if equipped) and EGR systen (if equipped)

Jun 03, 2011 | 1997 Toyota RAV4

1 Answer

The check enging light comes on then goes off. I foud out the code po118 engine coolant temp circut high input. is it the coolant temp sensor. if so how do I replace it. It is on a 2004 jetta tdi

According to

Because ECT (engine coolant temperature) sensor procedures vary depending upon their location, first locate the part. You may need to partially drain the engine coolant to prevent coolant spillage.
  • Disconnect the negative battery cable.
  • Unplug the ECT.
  • Then, unscrew it.
  • Reverse the removal procedures to install the new part.
  • Connect the negative battery cable to the battery.

    Related Parts:
Coolant Temperature Sensor printpage_icon.gif

0900c152801bfc38.jpg enlarge_icon.gifenlarge_tooltip.gif

Fig. Remove the coolant temperature sensor
The coolant temperature gauge sensor is a temperature-variable resistor, or thermistor. As coolant temperature increases, the resistance of the sensor decreases or decreases, depending on the type of sensor.
A1 and A2 platforms use a different type of circuit that A3 vehicles. On A1 and A2 vehicles, the circuit is a "resistance to ground" type. A3 vehicles use a "variable voltage" type, where a voltage is supplied to the sensor. Because of the circuitry design on A3 vehicles, testing of the coolant temperature gauge is limited.
The engine coolant temperature gauge uses a heat sensitive sending unit to transmit an electrical signal to the gauge. The sending unit is a heat sensitive variable resistor that is located on or near to the cylinder head and threads into an engine coolant passage. The sensors are a Negative Temperature Coefficient (NTC) type. As the temperature increases, the electrical resistance of the sensor decreases. As the coolant temperature changes, so does the resistance of the sensor. The gauge is calibrated within the operating range of the sensor and interprets the resistance value to display the coolant temperature.
Beginning with model year 1994, the engine coolant gauge and the Engine Control Module (ECM) temperature sensors were combined into one sensor with 4 terminals. The basic operation remains the same in that their resistance decreases as the coolant temperature increases, however the actual resistance values of the 2 sensor circuits are different. The electrical connector of the 4-wire terminal sensor ( 1 and 2 ) is keyed to prevent improper connection of the sensor's electrical circuit.

0900c152801bfc39.jpg enlarge_icon.gifenlarge_tooltip.gif

Fig. Beginning with model year 1994, the Engine Coolant Temperature Sensors combined the sensors for the ECM and the gauge into one sensor-1997 2.8L V6 sensor shown

0900c152801bfc3a.jpg enlarge_icon.gifenlarge_tooltip.gif

Fig. The electrical connector for the combined temperature sensors is keyed to avoid improperly connecting the sensor's wiring-1997 2.8L V6 connector shown

Oct 17, 2010 | 2004 Volkswagen Jetta

1 Answer

Where is the coolant sensor on a 93 century. 3.3 v6 I can't find where it is located. Top or bottom? Front or back?

A variety of sensors provide information to the ECM/PCM regarding engine operating characteristics. These sensors and their functions are described below. Be sure to take note that not every sensor described is used with every engine application. Coolant Temperature (ECT) The Engine Coolant Temperature Sensor (ECT) is a thermister (a resistor which changes value based on temperature) mounted on the engine coolant stream. As the temperature of the engine coolant changes, the resistance of the coolant sensor changes. Low coolant temperature produces a high resistance (100,000 ohms at 40°C/40°F), while high temperature causes low resistance (70 ohms at 130°C/266°F). The ECM/PCM supplies a 5 volt signal to the coolant sensor and measures the voltage that returns. By measuring the voltage change, the ECM/PCM determines the engine coolant temperature. The voltage will be high when the engine is cold and low when the engine is hot. This information is used to control fuel management, IAC, spark timing, EGR, canister purge and other engine operating conditions. A failure in the coolant sensor circuit should either set a Code 14 or 15. These codes indicate a failure in the coolant temperature sensor circuit.
It looks like the above, under hood, passenger side, upper engine area, mounted in front side of water outlet (according to

Oct 08, 2010 | Buick Century Cars & Trucks

1 Answer

My radiator fan is not working on my 2006 Dodge Charger

Hi, If you have truble code check/service engine soon light on,then go to your local Autozone part store for a free scan. If not,i'm going to start with haveing you check the cooling fan relay,this can be found in the power distribution box,this can be found in the engine compartment.I would change places with another relay with the same number on it. If this takes care of it,buy a new relay and it was an easy fix. If not here's tests you will have to do as long as you have a digital volt meter.

Operation printpage_icon.gif

The Engine Coolant Temperature (ECT) sensor is used to sense engine coolant temperature. The sensor protrudes into an engine water jacket.
The ECT sensor is a two-wire Negative Thermal Coefficient (NTC) sensor. Meaning, as engine coolant temperature increases, resistance (voltage) in the sensor decreases. As temperature decreases, resistance (voltage) in the sensor increases.
The PCM compares the ECT, Intake Air Temperature (IAT), and Ambient Air Temperature (AAT) under cold start conditions. Following a start to run delay time, the sensor values are compared. If the one sensor value is not within a specified range of the other two sensors, the value is determined to be irrational

2.7L, 3.5L & 5.7L Engines

  1. Turn the ignition off.
  2. Disconnect the Engine Coolant Temperature Sensor (ECT) harness connector.
  3. Turn the ignition on.
  4. With a scan tool, read the ECT sensor voltage.
  5. The sensor voltage should be approximately 5.0 volts (plus or minus .1 volt) with the connector disconnected.
  6. Turn the ignition off.
  7. Connect a jumper wire between the (K2) Engine Coolant Temperature Sensor (ECT) signal circuit and the (K900) sensor ground circuit in the ECT harness connector.
  8. Turn the ignition on.
  9. With a scan tool, read the voltage.
  10. The sensor voltage should be approximately 0.0 volts (plus or minus .1 volt) with the jumper wire in place.
  11. If voltage is present as stated suspect faulty ECT sensor.

I hope this helps,Thank You for using fixya, iluv2fish..... Ray.......

Jun 30, 2010 | 2006 Dodge Charger

2 Answers

Heating System

The Engine Coolant Temperature (ECT) sensor is mounted in the intake manifold and sends engine temperature information to the ECM. The ECM supplies 5 volts to the coolant temperature sensor circuit. The sensor is a thermistor which changes internal resistance as temperature changes. When the sensor is cold (internal resistance high), the ECM monitors a high signal voltage which it interprets as a cold engine. As the sensor warms (internal resistance low), the ECM monitors a low signal voltage which it interprets as warm engine.
0900c1528008f125.jpgFig. 1: View of the Engine Coolant Temperature (ECT) sensor 0900c1528008f126.jpgFig. 2: Engine Coolant Temperature (ECT) sensor locationTESTING
See Figures 3 and 4
  1. Remove the ECT sensor from the vehicle.
  2. Immerse the tip of the sensor in container of water.
  3. Connect a digital ohmmeter to the two terminals of the sensor.
  4. Using a calibrated thermometer, compare the resistance of the sensor to the temperature of the water. Refer to the engine coolant sensor temperature vs. resistance illustration.
  5. Repeat the test at two other temperature points, heating or cooling the water as necessary.
  6. If the sensor does not meet specification, it must be replaced.
0900c1528008f120.jpgFig. 3: Intake Air Temperature (IAT) and Engine Coolant Temperature (ECT) sensor wiring diagram 0900c1528008f095.jpgFig. 4: ECT sensor temperature vs. resistance values

Oct 01, 2008 | 1993 GMC Sierra

1 Answer

Temperature gauge

ENGINE COOLANT TEMPERATURE SENDER8218692.gif 1. Using an ohmmeter, measure the resistance between terminal 2 and ground. 2. If the resistance value is not as shown below, replace the temperature sender. Temperature (°C) 60 85 110 125 Resistance (Ω) 119.4 48.9 25 15.8

Jun 13, 2008 | Hyundai Motor 2003 Elantra

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