2004 Chevrolet Trailblazer ABS

Auto Repair Questions, Chevy Comments Off on 2004 Chevrolet Trailblazer ABS
Oct 112017

Chevy Trailblazer

My wife’s car has had an abs light on since right after we bought it. I had the codes read. They said it was the wheel speed sensor. I changed out both wheels speed sensors and put brand new brake pads on the front and back as well as new calipers all the way around. She said she drove it today the light still on and it was raining. She was coming to a stop sign and hit the brakes. It made an awful noise and it didn’t want to come to a stop. I have replaced the master cylinder and I have bled the brakes. I have also sanded down all the ground leads and put them back on and sprayed with undercoating as stated. Someone told me it could be the EBCM what should I do or change?


The description of what your wife told you would indicate the ABS was functioning properly. When the roads are wet or icy the ABS motor will activate, making a groaning noise, this prevents the wheels from locking up. When the ABS is activated the light may illuminate temporally and generally goes back off. If the light is on continuously the ABS will not function.

If you want to make sure the ABS doesn’t come and go you can disable the function by removing the ABS fuse or relay. Doing so will allow the brakes to function like all the old cars used to without ABS. Learning to brake a little earlier will help slow the car and also cause your brake pads and rotors to last longer. You can drive the car this way as long as you like but the ABS light will remain on.

If you want to repair the ABS system the use of a scan tool will be required for individual testing of components.

Antilock Brake System (ABS) Warning light

With the Anti-Lock Brake System (ABS), this light will come on when you start your engine and may stay on for several seconds, that is normal.

A chime may also sound when the light comes on.

If the light stays on, or comes on when you are driving, your vehicle needs service. When the regular brake system warning light is not on, you still have brakes, but you do not have anti-lock brakes. If the regular brake system warning light is also on, you do not have anti-lock brakes and there is a problem with your regular brakes. See Brake System Warning Light earlier in this section.

The ABS warning light should come on briefly when you turn the ignition key to RUN. If the light does not come on then, have it fixed so it will be ready to warn you if there is a problem.

Antilock Brake System

When wheel slip is detected during a brake application, the ABS enters antilock mode. During antilock braking, hydraulic pressure in the individual wheel circuits is controlled to prevent any wheel from slipping. A separate hydraulic line and specific solenoid valves are provided for each wheel. The ABS can decrease, hold, or increase hydraulic pressure to each wheel brake. The ABS cannot, however, increase hydraulic pressure above the amount which is transmitted by the master cylinder during braking.

During antilock braking, a series of rapid pulsations is felt in the brake pedal. These pulsations are caused by the rapid changes in position of the individual solenoid valves as the EBCM responds to wheel speed sensor inputs and attempts to prevent wheel slip. These pedal pulsations are present only during antilock braking and stop when normal braking is resumed or when the vehicle comes to a stop. A ticking or popping noise may also be heard as the solenoid valves cycle rapidly. During antilock braking on dry pavement, intermittent chirping noises may be heard as the tires approach slipping. These noises and pedal pulsations are considered normal during antilock operation.

Vehicles equipped with ABS may be stopped by applying normal force to the brake pedal. Brake pedal operation during normal braking is no different than that of previous non-ABS systems. Maintaining a constant force on the brake pedal provides the shortest stopping distance while maintaining vehicle stability.

Programming the Traction Control Automatic Engagement Feature

The automatic engagement feature may be programmed so that the traction control system activates or does not activate automatically at the start of each ignition cycle. In order to change the status of the automatic engagement feature, perform the following procedure:

Important Failure to follow the correct procedure may cause DTC C0283 to set in EBCM memory.

  • Park the vehicle and apply the parking brake.
  • Unlock the ignition and shift the transmission into NEUTRAL (N).
  • Turn the ignition ON, engine OFF.
  • Press and hold the brake pedal and the accelerator pedal.
  • Press and hold the traction assist switch for 5 seconds.
  • Release the brake and accelerator pedals and the traction control switch.
  • Turn the ignition OFF.

Brake lines 2000 Chevy Impala

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Oct 092017

2000 Chevy Impala

My 2000 Chevy Impala LS 3.8 motor brake lines are shot. Wondering how much it’s going to cost me to replace them. I believe it’s only the front ones.


Brake line Cost

If you are referring to the brake hoses that attach to the calipers it shouldn’t take more than a hours worth of labor. Around $100 plus parts and tax of course. The labor guide does not reference replacing the brake lines and will normally be charged by the hour for how ever long it takes. I wouldn’t think any longer than a couple of hours plus parts.

Oct 052017

1994 Chevy Corsica

I have a Chevy and it starts up but when you put in gear it stalls would it be the starter or something else?


Something else. The starter is used to “start” the engine and is disengaged once it starts.  The most common cause for this would be the TCC Torque Converter Clutch solenoid. In most cases if you can unplug the TCC solenoid (5 in diagram) at the transmission and the stalling issue will go away. However the converter will no longer lock up. This will leave you with the impression that you no longer have overdrive. Rest assured, you can drive the car this way for as long as you would like or until you decide to drop some serious coin and have it fixed.

TCC Solenoid location diagram 1994 Chevy Corsica

The TCC Solenoid

The TCC solenoid is what actually causes the TCC to engage and disengage.

When the TCC solenoid receives a signal from the ECM, it opens a passage in the valve body and hydraulic fluid applies the TCC. When the ECM signal stops, the solenoid closes the valve and pressure is vented causing the TCC to disengage. If the TCC fails to disengage when the vehicle comes to a stop, the engine will stall.

Source: ThoughtCo.com

Oct 052017

2000 Chevy Malibu

AC blower controls

I’m having issues with AC blower controls flap will go from face to feet after a few minutes then comes back randomly.
Recently found out I had a leak on AC compressor and had it replaced at a shop. We have had issues with my AC button on my AC Heater control switch. When I would push the AC switch and start driving down the road then it would would randomly turn off by itself. Looked up online and and seems to be a common issue with several GMs around that year. I saw a video on how to fix on your own (didn’t think I would be that crafty) so I just bought a new AC Delco AC Heater control switch. I installed the control switch and for the first time in a long time I had continuous cold AC.

Seems the face vents go out

But now it seems another issue has popped up. When I get into car and turn on air I always have just regular air going thru the top face vents. I hardly ever use the feet fan even in winter. The AC will be running fine then it seems the face vents go out and only can feel a lower feet vent. This isn’t permanent as while driving it will switch back to face or after parking. Is this an electrical, vacuum or bad new switch? Is the flap controlled by a vacuum or some type of electrical motor?
Also we had an unusually cool night and I tried something new I had run the face vent with just warm air and it stayed to face vents the whole trip. So not sure if that will help in anyway but thought I would include it.
My car has 159268 miles. My car has an automatic transmission. It has the 3.1 L V6 engine.


This vehicle is equipped with vacuum actuators that control the opening and closing of the vent doors and temperature blend door. So there is a chance that you may have a small vacuum leak or failing actuator. The fact that once you are driving for a while gives it a chance to build up some vacuum pressure. This allows the actuators to work for a while until they loose vacuum again.

vacuum acuator diagram 2000 Chevy Malibu

  1. Actuator Vacuum Hose
  2. Vacuum Actuator
  3. Vacuum Hose Harness
  4. Harness Connection

HVAC Air Delivery/Temperature Control Circuit Description

The vacuum actuators move the air valves in the HVAC system (except the temperature valve). Vacuum is applied to the actuators through the mode selector in the heater A/C control assembly. The mode selector consists of a rotary vacuum switch. The rotary vacuum switch supplies vacuum to the vacuum actuators according to the operating mode selected by the driver. A small servo motor moves the air temperature actuator. The small servo motor positions the door according to the voltage level from the temperature selector in the heater A/C control assembly. The temperature selector is a potentiometer positioned by the temperature control knob on the front of the heater A/C control assembly.

Air Temperature Actuator

When the ignition switch is in the RUN position, battery voltage is applied to the air temperature actuator. The actuator receives ground at all times through the following components:
•CKT 251
•Ground G204

The temperature selector is a potentiometer with a wiper arm. The wiper arm is electrically tied to the air temperature input through CKT 733.

When the temperature selector is moved between COLD and HOT, voltage to the control input varies between 1 and 12 volts. The temperature valve motor solid state circuitry performs the following tasks:
•Looks at the control input voltage
•Moves the motor to correspond to the control input voltage

The temperature valve moves for the following reasons:
•In order to allow the air to pass through the heater core
•In order to allow the air to pass around the heater core

This control achieves the desired passenger compartment temperature.

Sep 182017

Chevy Suburban 2005

I am getting code P0306 NO. 6 Cylinder misfire. I have changed out the injector, coil, spark plug wire & spark plug. My car is still running rough and code still shows up. What is wrong?


Chevy Code P0306

Chevy Code P0306 means that the cylinder 6 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 6.

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring.

Chevy Code P0306 Possible causes

  • Faulty spark plug 6
  • Clogged or faulty fuel injector 6
  • Faulty ignition coil 6
  • Fuel injector 6 harness is open or shorted
  • Fuel injector 6 circuit poor electrical connection
  • Ignition coil 6 harness is open or shorted
  • Ignition coil 6 circuit poor electrical connection
  • Insufficient cylinder 6 compression
  • Incorrect fuel pressure
  • Intake air leak
Sep 122017

2011 Chevy Equinox

Looses oil

This auto looses oil. Where I don’t know where none on driveway or garage floor. It makes a diesel sound when accelerating, when its low on oil, check oil level and its down, put in a quart oil and runs great for a while,and I do put in Dexos 5w30


You have two things going on. The diesel sound when accelerating can be cured by using high octane fuel. If you already are, switch stations the next time it needs filled up and use the highest octane they have.

As for the oil consumption. The engine is burning it internally if there are no signs of external leaks.

TSB UPDATE

May 22, 2016 — Owners of 2011 Chevrolet Equinox and 2011 GMC Terrain SUVs who have complained about excessive oil consumption problems may receive help from General Motors based on technical service bulletin (TSB) 15285C.

Owners of the SUVs say their vehicles consume oil at excessively rapid rates and cause constant refills and repairs. The 2011 Chevy Equinox and GMC Terrain SUVs are equipped with 2.4-liter gas engines, vehicles that have come under previous service bulletins for the same oil consumption issues.

GM describes excessive oil consumption as a vehicle that uses a quart of oil every 2,000 miles or less and blames the problem on wearing of the piston rings.

However, other owners have complained about the results of those expensive engine repairs.

What Consumers Say

“According to invoice replaced 1 Piston, gasket and chain! It now runs worse then before! Idles at 500 rpm.” – 2011 Chevrolet Equinox owner / El Paso, Texas

Chevy and GMC dealers were told in previous technical service bulletins to install updated engine control module calibration and perform an oil consumption test. This time dealers are told to diagnose the problem and replace the pistons.

General Motors says repairs will be made free of charge based on warranty coverage extended to 7.5 years or 120,000 miles, whichever comes first. The coverage begins from the date of sale of the SUV.

If you own a 2011 GMC Terrain or Chevy Equinox and experience excessive oil consumption, contact your local dealership and ask about TSB 15285C.

Source: http://carcomplaints.com/news/2016/chevy-equinox-gmc-terrain-oil-consumption-bulletin.shtml

Sep 112017

Chevy Truck

My girl was driving and put my manual transmission into 2nd gear while driving about 65 mph. She pulled over, truck was still barely running. She turned it off now it will not start. Where do i start?


Follow the above link and you will find a no start diagnostic chart. This is a step by step chart that will guide you though the no start diagnostic process.

Sep 062017

2008 Chevy Impala

The windows will not roll down on my 2008 Chevy Impala


Check to make sure you have power going to the master control switch(drivers door switch). If you hear it trying to do something but no movement, replace the window motor and regulator assembly.

Power Windows Operation

The switches on the driver’s door armrest are used to control each of the windows. The power window switches work while the ignition is in ON/RUN, ACC/ACCESSORY, or while Retained Accessory Power (RAP) is active. See Retained Accessory Power (RAP) . Each passenger door has its own window switch.

To lower the window, press and hold the front of the switch to the first position until the window is at the desired level. To raise the window, pull up and hold the front of the switch.

Power Windows Wiring Diagram 2008 Chevy Impala

2008-chevy-impala-power-windows-1-of-1

Starter clicks 1994 Chevy Silverado

Auto Repair Questions, Chevy Comments Off on Starter clicks 1994 Chevy Silverado
Aug 232017

Chevy Silverado 1500

Starter clicks

Starter clicks when I turn it over take bolts out of starter and let starter hang grounded to the frame and it works is this a bad starter?


One hard click indicates a bad starter. Several clicks or repeating clicks indicates a bad/weak battery.  Most likely a bad battery. The starter requires 250 amps from the to turn over the engine. Disconnected it does not have to draw as many amps to turn over air.

Test or replace the battery with a know good battery.

Starter Testing

  1. Make sure the battery is fully charged and that the battery terminal connections are clean and tight.
  2. Check the starter motor wiring for damage and/or open and shorted wires.
  3. Check that all starter motor electrical connections are clean and tight.
  4. If the starter motor cranks slowly and the solenoid clicks or chatters, test the starter motor as follows:
    A.Turn the ignition key to the start position.
    B.Use a Digital Volt Ohm Meter (DVOM) set to read voltage. Measure the cranking voltage at the battery terminal posts.
    C.If the voltage is less than 9.6 volts check the battery.
    D.If the battery voltage is 9.6 volts or more continue with the test.
    E.Connect the negative lead of the DVOM to the battery negative terminal and the positive lead of the DVOM to the engine block.
  5. If the voltage is less than 0.5 volts, attach the positive lead of the DVOM to the starter B terminal and crank the engine.
  6. If the voltage reading is less than 9.0 volts, replace the starter motor.
  7. If the starter motor does not crank and there is no sound from the solenoid, test the starter motor as follows:
    A.Turn the headlights and the dome light on.
    B.Turn the ignition key to the START position.
    C.If the lights stay bright, turn the radio, heater and turn signals on.
    D.If the accessories you have turned on do not operate properly, check the bulkhead connector fusible link and the ignition switch connections.
    E.If the accessories operate properly, continue with the test.
    F.Make sure the ignition key is still in the START position.
    G.If your vehicle is equipped with a automatic transmission, using a Digital Volt Ohm Meter (DVOM) set to read voltage, connect the negative lead of the DVOM to the battery negative terminal and the positive lead of the DVOM to the starter S terminal.
    H.If the voltage is 9.6 volts or more, replace the starter motor.
    I.If the voltage is 9.6 volts or less, attach the positive lead of the DVOM to the ignition switch solenoid terminal.
    J.If the voltage is 9.6 volts or more, repair the purple wire from the ignition switch to the starter.
    K.If the voltage is less than 9.6 volts, replace the ignition switch.
    L.If your vehicle is equipped with a manual transmission, using a Digital Volt Ohm Meter (DVOM) set to read voltage, connect the negative lead of the DVOM to a good known ground and the positive lead of the DVOM to the neutral/start switch. Turn the ignition key to the START position and depress the clutch.
    M.If there is more than 9.6 volts present at one terminal, test the switch connector and adjustment. If the adjustment and connector are functioning properly, replace the switch.
    N.If there is less than 9.6 volts present at both terminals, make sure the ignition key is still in the START position.
    O.Test the voltage at the ignition switch solenoid terminal.
    P.If the voltage is 9.6 volts or more, repair the yellow feed wire from the ignition switch.
    Q.If the voltage is less than 9.6 volts, replace the ignition switch.
Jul 152017

Chevy Cavilier

Will not start

My 2003 Chevy Cavalier will not start. The engine spins and the car is getting fuel pressure to the fuel rail. I was driving and suddenly it stalled out. It would not turn on. I had to tow it home. The battery, alternator, starter, are good. And the fuel pressure is good at 50psi. My car has new Spark plugs and oil. I also changed out the crankshaft position sensor. Can you please help me figure out whats wrong with my vehicle.


We have created a diagnostic chart for just an occasion.