SILVERADO 1500 AC LIGHT FLASHES 3 TIMES AND SHUTS OFF I REPLACED THE AMBIENT TEMP SENSOR BUT THE AC STILL DOESNT COME ON

SOURCE: Ambient temp sensor not working

the sensor is located under the front bumper.or the grill

SOURCE: 99 chevy 1500 with DRL feature; headlights won't

change the headlight switch!! itself its broken inside the unner contacts

Marvin

• 85242 Answers
• Posted on Oct 26, 2010

SOURCE: '08 silverado. dash board diplays, engine running

P0128 OBD-II Trouble Code Technical Description

Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
What does that mean?

This means that the engine's PCM detected that the engine has not reached the required temperature level within a specified amount of time after starting the engine. The intent of the P0128 code is to indicate a faulty thermostat. Similar codes: P0125

In determining the engine did not reach a "normal" temperature, it takes into account the length of time the vehicle has been running, the intake air temperature (IAT) sensor reading, the engine coolant temperature (ECT) sensor reading, and the speed of the vehicle.
FB.init("dd7d9e9681341cde77587bc6a2029f6f"); OBD-Codes.com on Facebook Symptoms

You will likely not notice any drivability problems other than the MIL illumination.

Causes

A code P0128 may mean that one or more of the following has happened:

• Low engine coolant level
• Leaking or stuck open thermostat
• Faulty cooling fan (running too much)
• Faulty coolant temperature (ECT) sensor
• Faulty intake air temperature (IAT) sensor

Past experience indicates that the most likely solution is to replace the thermostat. However here are some suggestions on troubleshooting and repairing a P0128 OBD-II code:

• Verify coolant strength & level
• Verify proper cooling fan operation (check if it's running more than it should). Replace if necessary.
• Verify proper engine coolant temperature (ECT) sensor operation, replace if necessary.
• Verify proper intake air temperature (IAT) sensor operation, replace if necessary.
• If the above items check out good, replace the thermostat

SOURCE: 2002 Buick LeSabre no heat,

Hi

The first thing to check is the coolant level and to insure the thermostat is working. Usually just putting in a new thermostat is the best thing to do. When you have already replaced it then make sure there are no air bubbles in the cooling system. Here's the procedure for bleeding the cooling system....

Loosen the air bleed bolt in the thermostat housing, then fill the radiator to the bottom of the filler neck with the coolant mixture. Tighten the bleed bolt as soon as coolant starts to run out in a steady stream without bubbles.

With the radiator cap off, start the engine and let it run until warmed up (radiator fan comes on at least twice). Then, if necessary, add more coolant mix to bring the level back up to the bottom of the filler neck.

Put the radiator cap on tightly, then run the engine again and check for leaks.

Check the links for the diagram...

http://z.about.com/d/autorepair/1/0/q/5/62455816.gif

The next thing to check is the Heater Control Valve. With the heat selector on HOT, the valve should be open. Feel the heater hoses, they should be equally hot on both sides. If not, the valve is not opening and needs to be replaced.

http://z.about.com/d/autorepair/1/0/r/5/78721688.gif

If after this you still have no heat, you need to check the HVAC controls. There is a cable that goes from the temperature selector switch to an air mix door. Check to see that it is still attached on both ends and not kinked. Its been seen many cables bend and distort at the air mix door.

http://z.about.com/d/autorepair/1/0/s/5/56533993.gif

Please get back to us if you have further query else please accept the suggestion.

SOURCE: Ambient temp sensor replacement

The ambient air temp sensor is located on the radiator support bracket at the top (see figure below, item 1)

Testimonial: "Thank you for assisting me. "