Aug 032016

1997 Buick Park AvenueI have a 1997 Buick Park Avenue and when I flip the switch to turn my high beams on, they don’t come on. And my dash lights and side marker lights go off also. I have replaced the switch with a new one and it didn’t fix it.


Looking at the wiring diagram it would appear as the only thing in common with both the high beam switch and the dash lights would be the Lamp Control Module other than the switch.

Headlight and High Beams Wiring Diagram 1997 Buick Park Avenue

Aug 032016

2001 Buick CenturyI have a problem with my cooling system in my 1999 Buick Century Custom. I am leaking coolant. I tried stop leak, is not working. I can drive for long periods of time, open the radiator cap without any problem. It is cold to the touch and there is no pressure when I release the cap.


Sounds like your thermostat may be stuck in the open position as well as leaking coolant. Also the radiator cap may be faulty if no pressure is building or you have a large leak. You will need to use a cooling system pressure tester.

How to find leaking coolant

  • With the engine off,  Remove the radiator cap and attach the pressure tester
  • Pump up the tester to apply pressure on the system. Pressure should be the same as the radiator cap. (around 17-20 psi)
  • Look for the leak, put cardboard underneath to help if needed. If no external leak is found, remove spark plugs and look for coolant to come out spark plug holes.
  • Repair the leak
  • Pump up the tester again
  • Watch for the pressure to hold, this indicate no more leak in the system.

Coolant Description

Caution! Antifreeze can be added to raise the boiling point of the coolant, but too much will affect the freezing point. Do not use a solution stronger than 70 percent antifreeze, as the freeze level rises rapidly after this point. Pure antifreeze will freeze at -22°C (-8°F).

GM Goodwrench DEX-COOL® was developed in order to last for 240,000 km (150,00 miles) or 5 years, whichever occurs first. Follow the instructions in Draining and Filling Cooling System . Use only GM Goodwrench DEX-COOL® or HAVOLINE® DEX-COOL® when adding or changing the coolant.

A 50/50 mixture of ethylene glycol DEX-COOL® and water will provide the following protection:

  • Give freezing protection down to -37°C (-34°F)
  • Give boiling protection up to 129°C (265°F)
  • Protect against rust and corrosion
  • Help keep the proper engine temperature
  • Let the warning lights and gauges work as they should.
Jul 252016

2002 Buick LesabreThe 2002 Buick Lesabre blower motor at times does not come on and then will start blowing or at other times the blower motor won’t come on for a long while but will sometimes start blowing after a restart.


This is form loose wiring, bad wiring connection or failing blower motor. Most common would be a failing blower motor. The blower motor has internal brushes that wear and begin to make weak contact. Replacing the motor should take care of the issue.

The 2002 Buick Lesabre Blower motor Replacement without Vent Tube


The 2002 Buick Lesabre Blower Motor Replacement with Vent Tube


The 2002 Buick Lesabre Blower Motor Control Processor

The blower motor control processor is an interface between the HVAC control module and the blower motor. The blower motor speed control, battery positive voltage and ground circuits enable the control processor to operate. The HVAC control module provides a PWM signal to the control processor in order to command the blower motor speed. The processor supplies 12 volts to the blower motor through the blower motor voltage supply circuit. The control processor uses the blower motor ground as a low side control to adjust the blower motor speed.

Air Speed

 The blower motor forces air to circulate within the vehicle’s interior. The vehicle operator determines the blower motor’s speed by placing the blower motor switch in a desired speed position or by selecting automatic operation. The blower motor will only operate if the blower motor switch is in any position other than OFF, and the ignition switch is in the RUN position. In manual operation, once a blower speed is selected, the blower speed remains constant until a new speed is selected. In automatic operation, the HVAC control module will determine what blower speed is necessary in order to achieve or maintain a desired temperature.

As the requested blower speed increases, the following conditions occur:

   •  The IPM increases the amount of time that the blower motor speed control circuit is modulated to ground.
   •  The voltage and duty cycle, measured between the blower motor speed control circuit and ground, decrease.

As the requested blower speed decreases, the following conditions occur:

   •  The IPM decreases the amount of time that the blower motor speed control circuit is modulated to ground.
   •  The voltage and duty cycle, measured between the blower motor speed control circuit and ground, increase.
Jul 072016

2002 Buick LesabreI keep having to change my lights because they keep burning out, headlights, taillights, blinkers, etc. I just changed the turn signal last night. When I went to drive it this morning out again. Tried to replace, now it won’t work at all. What could be causing the lights to go out one by one? The car only has 107,000 miles on it.


Age is the most common reason for a bulb to fail. No different then the light bulbs in the house. The exact timing of each bulb going out is not predictable.

  1. Corrosion
  2. Loose connections
  3. Poor manufacturing of the bulbs
  4. Possible exposure to moisture
  5. Defective wiring harness

The only thing these all share in common is the ground connection. And they would not work at all without it.

Jun 272016

Buick EnclaveWhen I press the air conditioning button on the console display panel; it blinks 3 times, but won’t engage the ac. The owner’s manual says it is the sensor. Where is it located.


There are four air temperature sensors.  Two are on the right and two are on the left. There is an upper and lower.

Temperature Sensor Upper Right Side Location

Air temperature sensor location 2014 Buick Enclave

Temperature Sensor Upper Left Side Location

Air temperature sensor location upper left 2014 Buick Enclave

Temperature Sensor Lower Left Side Location

Air temperature sensor lower left location 2014 Buick Enclave

Temperature Sensor Lower Right Side Location

Air temperature sensor location lower right 2014 Buick Enclave

Other information pertaining to the same issue

The red light blinks three times if you press the air conditioner button when it is below 40. The AC will not work below 40F unless its in the defrost mode, this has been designed into the system for many years to prevent accidental running of the AC in the winter when not needed.

Ive read that the exterior temp sensor- will not take an immediate reading..
and by design may take some miles of driving before it takes a reading- and then displays the updated info on your dash.
Since you have the digital AC system.. the sensors may be reading the PREVIOUS low temp which was 40 or less…
Thus your re-circulation will flash the light…
2 min later- once you’ve driven- a new temp reading has been taken- and now above 40– and now it will work and no more flashing 3 times…

Thats what I think may be happening…. just an idea.

Jun 152016

1998 Buick LesabreJust replaced my battery but something keeps draining it. I checked my alternator and it’s still good. Checked all wires and connections and they all look fine. What could be draining the battery?


An internal short in the battery will mostly go unnoticed. Odds are the battery is greater than 4 years old. Replace the battery and all should be fine once more.

1998 Buick Lesabre Battery Replacement


Battery Charge Low or Completely Discharged

  1. Measure the battery voltage at the battery terminals using a digital multimeter.
   –  A reading of less than 11 V indicates that the initial charging will be very low.
   –  Some time may pass before the battery accepts current in excess of a few milliamperes.
  1. Set the battery charger to the highest setting.
  2. If necessary, disable the polarity protection circuitry:
   –  This circuitry, available on most chargers, prevents charging unless the charger leads are properly connected to the battery terminals.
   –  A completely discharged battery may not have enough voltage in order to activate this circuitry, even though the leads are properly connected, implying that the battery will not accept a charge.
   –  Most chargers have an override or a bypass function. This function will turn on the charger and charge a low voltage battery.
  1. The required battery charge time varies according to the voltage capabilities of the battery charger. A charger of less than 14 volts may take up to 16 hours before the battery appears to be accepting current.
  2. Perform the following calculation in order to determine the amount of time that the battery may need to be charged:
   –  The reserve capacity rating on the battery label is the number of ampere-hours of charge required in order to produce the green hydrometer dot.
   –  After the meter on the charger starts to show current flow, note the number of amps being accepted.
   –  Determine the reserve capacity of the battery.
   –  Divide the reserve capacity by the number of amps shown on the meter in order to determine how many hours of charging is needed.
  1. When the green dot appears in the hydrometer, discontinue charging.
  2. If the green hydrometer dot is not visible after an ampere-hour charge equal to twice the reserve capacity rating, replace the battery.
  3. After charging, load test the battery.
Jun 012016

1990 Buick RivieraMy son put two stroke gas in his empty gas tank and now it starts but then dies right away. What should he do?


The 2-stroke mix shouldn’t make a big difference at all. If the car has been run out of gas, you will need to prime the fuel system. This can be done by cycling the ignition key on and off 10 times, pausing 5 seconds between each. This will refill the fuel lines and fuel filter in order to allow proper fuel pressure to each fuel injector.

Jun 012016

2001 Buick CenturyI think someone put a TEE in the vacuum line for the brakes and put water down the hose so I have water in my engine, it’s not seized up but how do I get the water all out and get my car running again?


Change the engine oil, run the engine for a couple hundred miles and change it again. Do not run the engine until you change the oil.

Signs of water in oil

  1. Oil level will be higher than normal or show over filled on dipstick
  2. Oil will appear milky
May 132016

2007 Buick Lacrosse Code P2138I have replaced the gas pedal unit which includes the sensor 2 months ago on my 2007 Buick Lacrosse 3.8L. Has been working fine. Then the other day the check engine light came back on with the same code P2138 that says (reduce engine power) which means gas pedal and senor unit again. The problem I’m having the check engine light comes on, I drive it a few times it goes away, but then it will come on again a few days later back and forth, back and forth. What could be causing this to happen please.


The Engine Control Module (ECM) has detected that the APP sensor 1 and APP sensor 2 disagree more than 4.5 percent for less than 1 second. This turns on the check engine light. It is possible that the wiring or connections are faulty. Also possible that the parameters set in the ECM need to be reprogrammed. It is also possible that the “New” part is bad. I would anticipate the repair and part are covered under warranty and as such you should return the vehicle to the repair shop. There is a TSB – Technical Service Bulletin for the Code P2138 with reduced engine power which identifies a repair instrument panel to body harness connector. (see below)

CODE P2138 BUICK – Accelerator Pedal Position Sensor 1-2 Correlation

Code P2138 Possible causes

– Faulty Accelerator Pedal Position Sensor
– Accelerator Pedal Position Sensor harness is open or shorted
– Accelerator Pedal Position Sensor circuit poor electrical connection
– Faulty Electric Throttle Control Actuator

The Accelerator Pedal Position (APP) sensor is made up of 2 sensors that are housed inside one assembly. The Engine Control Module (ECM) supplies a separate 5-volt reference circuit and a low reference circuit for each of the sensors. The 5-volt reference for APP sensor 1 is supplied from the same source in the ECM as the 5-volt reference for the mass air flow (MAF) sensor and the fuel tank pressure (FTP) sensor. The 5-volt reference voltage for all of the sensors is supplied on separate ECM terminals, but the terminals are connected internally to a voltage supply. The APP sensor 1 sends a signal from the sensor to the ECM indicating the accelerator pedal position. The ECM actuates the throttle plates based on this information. If the ECM detects that the APP sensors are not within a predicted value from each other, DTC P2138 sets.

TSB 07-06-04-019E

Intermittent malfunction indicator lamp(MIL) illuminated, DTC P2138 with reduced engine power (repair instrument panel to body harness connector)

Affected models: 2005-2015 GM passenger cars and light duty trucks


  • Some customers may comment on an intermittent malfunction indicator lamp(check engine light) being illuminated with a message or an indicator that displays Reduced Engine Power.
  • The technician may observe on a scan tool DTC Code P2138 – Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History.

The condition may be caused by water intrusion into the instrument panel to body harness connector, which carries the APP Sensor signals to the ECM/PCM. The water intrusion results in a voltage difference between APP Sensor 1 and APP Sensor 3 that exceeds a predetermined value for more than a calibrated period of time, setting Code P2138.

Some examples of potential water leaks are: A-Pillar seals, Sunroof drain lines and windshield /cowl sealing.

The Fix:

  1. Verify that aftermarket equipment is not electrically connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5v reference or low reference circuits.
  2. Perform the diagnostic system check – vehicle.
  3. Locate the Instrument Panel to body harness connector, which may be located in and around the left hand kick panel area or inside the instrument panel. Depending on the vehicle and model year.
  4. Inspect for water leak in area. If necessary use a water hose to determine the source of the leak.
  5. Inspect the instrument panel to body harness connector terminals for corrosion and debris.
  6. If any corrosion or debris is observe, repair as needed.
  7. After completing the repair, verify the proper operation of the system.
Dec 182015

99 Buick regal would sometimes not crank or fire when you wanted but next time would start right up, once it died while driving and started back up. The coil packs, wires and plugs are replaced. Would crank and run great before, now it wont crank. Turns over but no fire it seems