Rick's Free Auto Repair Advice » Allure

Intermittent problems on GM vehicles

Rick — Thu, 08 Sep 2011 21:23:07 +0000

GM vehicles from the mid ’90′s to the present are known for faulty ignition switches. The problems are almost always intermittent. Intermittent starting, dying while driving, A/C to start blowing warm air or for the blower fan to stop (depending on which GM model we’re talking about), along with an ABS light. In fact, any time you see erratic or intermittent problems that could be electtrical in nature on a GM vehicle, you should immediately suspect the ignition switch. Always test the igntion switch during an intermittent problem to see if the switch is providing power (use a meter).Or, wiggle the wires going to the switch. GM techs replace so many of these that it’s almost automatic for them to head there first

In the case of the A/C the problem is usually the ignition switch heating up and not providing power to the A/C clutch and the ABS computer. If you want to diagnose the problem, buy a wiring diagram for your vehicle form eautorepair.net or alldata.com (there are way to many GM models to list their wiring diagrams here) and test for power at the switched terminals when the problem happens. Or, just replace the ignition switch.

For more information on this repair or any others for your vehicle, buy an online subscription to either Alldatadiy.com or eautorepair.net. Click on this link to compare the two services: Compare Alldata and Eautorepair.

If you just need information for a single repair and want to save money,eautorepair offers a lower price 1-week subscription for only $11.99. Or, if you’ll be working on this vehicle in the future, you can buy a 1-year subscription (Alldatadiy.com for $26.99, or eautorepair.net $29.99)

Alldatadiy.com

eautorepair.net

Both Alldata and Eautorepair offer professional grade shop manuals at a price you can afford. Check them out!.

P0332, Circuit Low Input (Bank 2) on GM products

Rick — Tue, 06 Sep 2011 04:10:36 +0000

Also P0335 and P0340

If you think you should replace the knock sensor after getting this code, think again. This is a perfect example of where a sensor can be telling the truth and the root cause of the problem is somewhere else. Here’s the scoop. Most late model engine use variable valve timing to change the opening and closing timing of the valves. The device that actually changes the valve timing is called the cam phaser (yeah, like on Star Treck). Some cam phasers use oil pressure to rotate the camshaft slightly to change the timing. That’s great when it’s working well. But if you’ve changed your own oil and used a viscosity that’s different from the manufacturer’s recommendations, you can screw up the phaser. For example, some people don’t believe the manufacturer’s recommendation to use 5W-30. So they change their oil with 10W-30. The slightly thicker oil can cause the phaser to respond more slowly to computer commands. And when the cam is out of phase from the commanded position, you can get pre-ignition, or pinging. Yup, if you used this oil and now have this trouble code, point your finger right at yourself.

The same holds true if you think you can get away with not changing your oil on time. Think sludge buildup isn’t a problem? Well guess what, sludge in a cam phaser can also cause trouble codes.

If you’re getting these codes and think it might be caused by oil, change your oil and filter and drive the vehicle first. Perhaps the clean oil can clear out the passages.

Here are a few other things that can cause this trouble code:

Check the electrical connector on the cam phaser. If you see oily buildup, disconnect the connector and check inside. Oil can sometimes seep into the connector and that would give false readings.

Alldatadiy.com

eautorepair.net

Both Alldata and Eautorepair offer professional grade shop manuals at a price you can afford. Check them out!.

A/C doesn’t work and ABS light on

Rick — Thu, 01 Sep 2011 17:53:39 +0000

GM vehicles are known for faulty ignition switches. The problems are almost always intermittent. One common symptom is for the A/C to start blowing warm air or for the blower fan to stop (depending on which GM model we’re talking about), along with an ABS light. The problem is usually the ignition switch heating up and not providing power to the A/C clutch and the ABS computer. If you want to diagnose the problem, buy a wiring diagram for your vehicle form eautorepair.net or alldata.com (there are way to many GM models to list their wiring diagrams here) and test for power at the switched terminals when the problem happens. Or, just replace the ignition switch.

Alldatadiy.com

eautorepair.net

Both Alldata and Eautorepair offer professional grade shop manuals at a price you can afford. Check them out!.

Performance Chip? GM Revokes Warranty on Chipped Vehicles

Rick — Fri, 18 Dec 2009 23:16:46 +0000

GM issued a technical service bulleting (TSB) #09-06-04—026 regarding revocation of warranty coverage on any GM vehicle in which the factory calibrations (software) has been removed or altered. The TSB applies to ALL GM gasoline passenger cars and trucks from 2006- present.

It’s important to note that GM is seeing enough damaged engines and transmissions to make this announcement. Here’s a direct quote from the TSB:

“When alteration to the GM-released engine or transmission control calibrations occurs, it subjects powertrain and driveline components (engine , transmission, transfer case, driveshaft and rear axle) to stresses that were not tested by General Motors. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy to cancel any remaining warranty coverage to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed – even if the non-GM control module calibration is subsequently removed.”

The TSB goes on to instruct the dealers on how to determine if the factory calibrations have been altered or removed. So don’t think you change restore the factory programming and tear into the dealer when they refuse to cover your warranty claim. They CAN tell what you’ve done.

So, if you’re planning on “chipping” your vehicle (which I do NOT recommend), be aware that you’re on your own and that the likelihood of damage to the engine and transmission increases dramatically.

Also, remember this: engine design is always a compromise between power, responsiveness, emissions, and fuel economy. You cannot change one variable without changing all the others. So, while chipping may increase power in one range of operation, you will pay for it in other areas. There’s no free lunch, despite what the chipmakers want you to believe.

Alldatadiy.com

eautorepair.net

Both Alldata and Eautorepair offer professional grade shop manuals at a price you can afford. Check them out!.

Hover your mouse over the REPAIR ARTICLES tab at the top of the page. The click on DIAGNOSTICS to search by SYMPTOM, TROUBLE CODE, or read TECH TIPS on how to diagnose a problem

Click on MAKE an MODEL to see all the articles I’ve written for your vehicle
Click on REPAIR TOPICS to read individual articles written for specific automotive systems

If you’ve had your car scanned and know the trouble code go to TROUBLE CODES

Here are some quick links to speed up your research

Click on the link below for speedy navigation:

ABS issues, how to bleed ABS brakes

Airbag issues or SRS light on

Alternator issues or how to test

Belt diagram or serpentine belt issues

Blower motor

Blower motor resistor

Brakes, brake issues, what kind of brake parts to buy, ABS issues

Car Alarms or Antitheft systems

Cooling system, Water pump, What type of coolant to use

Engine flush

Firing order, cylinder layout, finding #1 cylinder

MAF or MAP sensor

Oxygen sensors, How they work, How to change, How to test

PassLock or Passkey

Thermostat issues

Transmission flush

Serpentine belt diagrams

Window issues, power window motor, replace window regulator, glass adhesive

Headlights flicker on vehicle with daytime running lights

Rick — Sun, 06 Dec 2009 18:02:10 +0000

Every manufacturer has their share of problems with daytime running lights. Basically the system senses that the vehicle is running and the headlight switch is off. Programmed conclusion? Must be daylight, otherwise the driver would turn on the headlights. Other systems have light sensors. The Chrysler Daytime Running Light system gets screwed up by corrosion in the intelligent power module. Some GM vehicles fail due to a cracked Daytime Running Light resistor (computer provides power to the headlights, but runs it through a resistor to cut down on the headlamp brightness). Still another GM system runs the headlight commands through Daytime Running Lamp Module located behind the left side of the instrument panel. This module contains a diode that has a high failure rate. The module sends a command to the Daytime Running Lamps Relay located in the convenience center (firewall passenger side).

If you have the latter system, remove the relay and insert a jumper wire across the power terminals. See Relay Layout. If that fixes the problem, replace the relay. If it doesn’t, replace the Daytime Running Lamp Module.

Alldatadiy.com

eautorepair.net

Both Alldata and Eautorepair offer professional grade shop manuals at a price you can afford. Check them out!.

Hover your mouse over the REPAIR ARTICLES tab at the top of the page. The click on DIAGNOSTICS to search by SYMPTOM, TROUBLE CODE, or read TECH TIPS on how to diagnose a problem

Click on MAKE an MODEL to see all the articles I’ve written for your vehicle
Click on REPAIR TOPICS to read individual articles written for specific automotive systems

If you’ve had your car scanned and know the trouble code go to TROUBLE CODES

Here are some quick links to speed up your research

Click on the link below for speedy navigation:

ABS issues, how to bleed ABS brakes

Airbag issues or SRS light on

Alternator issues or how to test

Belt diagram or serpentine belt issues

Blower motor

Blower motor resistor

Brakes, brake issues, what kind of brake parts to buy, ABS issues

Car Alarms or Antitheft systems

Cooling system, Water pump, What type of coolant to use

Engine flush

Firing order, cylinder layout, finding #1 cylinder

MAF or MAP sensor

Oxygen sensors, How they work, How to change, How to test

PassLock or Passkey

Thermostat issues

Transmission flush

Serpentine belt diagrams

Window issues, power window motor, replace window regulator, glass adhesive

Anti-Theft Systems for GM Vehicles

Rick — Fri, 29 May 2009 16:33:00 +0000

GM has used a variety of anti-theft systems on their vehicles. When you get a no start, intermittent start, or start then die, you should diagnose the anti-theft system before you start replacing starting components. A tell-tale sign that you’ve got an anti-theft problem is a flashing “Theft” light. Here’s a brief primer on each system and what to look for.

Each GM anti-theft system disables different components. Some disable the engine starter, while others enable the starter but disable fuel injectors. None of them disable spark. So, first understand the difference between vehicle theft deterrent systems.

VAT
The VAT, or vehicle anti-theft was used primarily on 1986-88 Corvettes. The key had a pellet that was married to the vehicle anti-theft module at the factory. If the lock cylinder was turned or bypassed with the proper key installed, the system would disable the starter and kill the injectors. You could NOT perform a system “relearn.”

PassKey I, and II
Similar to the VATS system, these vehicles also used a pellet key. You can identify this system by looking at the key. It has a black resistor pellet with a thin metal edge running along the key. The system enables the starter, but shuts down the injectors after initial startup. So the vehicle would start, then die. This system has a “relearn” feature. It was used on these vehicles

Buick
Century 97-01
Park Avenue 91-96
LeSabre 92-99
Riviera/Reatta 90-01
Regal 94-99
Roadmaster 94-96

Cadillac
Eldorado 89-01
Seville 89-97
Fleetwood 92-96
Deville 90-99
Allante 89-93

Chevrolet
Camero 89-01
Corvette 89-01
Caprice/Impala 94-96
Lumina/Monte Carlo 95-97

Oldsmobile
Cutlass Supreme 94-97
Aurora 95-00
Regency/88 91-99
Toronado 90-93
Pontiac
Firebird 89-01
Grand Prix 94-96
Bonneville 92-99

PassKey III
This system uses a special key (PK3 stamped on the shoulder of the key) with a transponder under the rubber cover. The receiver module is located next to the lock cylinder. When the key is positioned next to the lock cylinder receiver module, it energizes the transponder which sends a coded signal to the receiver. The receiver module checks its memory to see if the signal is correct. If it is, the module sends a signal to the PCM to enable the engine. If the value is valid, the indicator light will remain steady for 2 seconds. You cannot test this system with an ohmmeter. You need a scan tool. If the signal is not correct, the PCM disables the injector and the starter and flashes the light once per second. If an illegitimate key is used or a system problem exists, the light flashes twice per second.

The system is used on:

Buick
Lesabre 2000-on
Park Avenue 97-on

Cadillac
Seville 98-on
Deville 2000-on

Oldsmobile
Aurora 01-on

Pontiac
Bonneville 2000-on

GM Minivans
Venture, Montana, Silhouette

Passlock
This system allows starter operation, then kills the injectors 1-2 seconds after startup. This is a “Hall-Effect” system. The key cylinder housing has a small magnet that rotates past the Passlock sensor. The sensor is powered and detects the rotation. The voltage on the sensor then drops to a specified value (there are 10 different values). There’s no pellet in the key. So basically this system is checking to see that a thief has not popped the lock cylinder to steal the vehicle. you have to perform a Powertrain Control Module (PCM) relearn procedure (need a programming scan tool). The Passlock system was used on:

Buick
Skylark 96-98

Chevrolet
Cavalier 95-on
Impala 2000-on
Malibu 97-on
Monte Carlo 2000-on

Oldsmobile
Achieva 96-on
Cutlass 97-on
Intrigue 98-on

All GM trucks 98-0n

SYSTEM DIAGNOSTICS

PassKey I and II System Diagnostics

There are 15 different key codes. Measure the resistance of the key pellet by connecting an ohmmeter to each side of the key pellet. Once you find the resistance value, remove the lower dash panels and locate two small wires (both white) that run down the base of the steering column. Disconnect the electrical connector where those wires terminate. Then connect an ohmmeter to that electrical connector and insert the key. The reading you get at the end of the two white wires should match the resistance value you got from the key. Next, turn the key. The value on your meter should NOT change or drop out. If it does, you will have to replace the key cylinder. It is COMMON for the wires to break from the key cylinder.

If you have the PassKey system and the engine cranks, runs, and quits AND the THEFT light is on (for about 5 seconds), here are the tests you should perform:

1) Disconnect the electrical connector at the deterrent module. Then turn the ignition switch to RUN while you test the voltage between the dark blue wire in the theft deterrent electrical connector (the one you just disconnected) and a ground point. You should see 5 volts. If you don’t get that voltage, check for an open or short between the dark blue wire and the PCM that supplies the voltage to the module.

If you DO get the 5 volts, turn the ignition off and reconnect the electrical connector. Pierce the insulation on the same wire (with a pin) or back-probe the wire in the connector. Turn the ignition to RUN. The voltage should now read 2.5 volts. If not, replace the theft module. THAT assumes you have already conducted the key pellet test (explained above) and that it passes the test. If you see 2.5 volts and the vehicle still won’t stay running, check the fuel pump relay.

Here’s how it works, The lock cylinder reads the resistance of the pellet in the key and transmits that data to the theft module. Meanwhile, the PCM provides 5 volts on the dark blue wire. When the theft module determines that the proper key has been inserted, it partially grounds the voltage on the dark blue wire. The PCM initially provides fuel injector pulse, but if it doesn’t sees a voltage drop on that dark blue wire, it cuts off the fuel injectors. That’s why you get a crank, start, engine shut down.

So, if the vehicle starts and then dies, AND THE THEFT LIGHT FLASHES, the module is not getting the proper signal from the lock cylinder or the module is bad.

Passlock
Testing this system is similar to the Passkey I and II systems. You want to check the voltage at the bottom of the steering column as you insert the key and rotate it check the yellow signal wire (should be 5 volts before you start the testing). Turn the key.

The value should drop. If it does not, you will have to replace the key cylinder. The “control module” for this system is built into the instrument panel control (IPC) in early years. In later years, the system is controlled by the Body Control Module (BCM), the Electronically Controlled Orifice-steering Assist (EVO), IPC and other systems. If you have to replace the lock cylinder or any of the control modules,

Passkey III

You cannot check this system with an ohmmeter. You will need a scan tool to watch the operation of the system and find the trouble code. Once you get the trouble code, follow the diagnostic procedure based on the specific code.

Some companies make PASSLOCK OVERRIDE SYSTEMS. I don’t have any experience with them. But if you want more information, click HERE

Alldatadiy.com

eautorepair.net

Both Alldata and Eautorepair offer professional grade shop manuals at a price you can afford. Check them out!.

Hover your mouse over the REPAIR ARTICLES tab at the top of the page. The click on DIAGNOSTICS to search by SYMPTOM, TROUBLE CODE, or read TECH TIPS on how to diagnose a problem

Click on MAKE an MODEL to see all the articles I’ve written for your vehicle
Click on REPAIR TOPICS to read individual articles written for specific automotive systems

If you’ve had your car scanned and know the trouble code go to TROUBLE CODES

Here are some quick links to speed up your research

Click on the link below for speedy navigation:

ABS issues, how to bleed ABS brakes

Airbag issues or SRS light on

Alternator issues or how to test

Belt diagram or serpentine belt issues

Blower motor

Blower motor resistor

Brakes, brake issues, what kind of brake parts to buy, ABS issues

Car Alarms or Antitheft systems

Cooling system, Water pump, What type of coolant to use

Engine flush

Firing order, cylinder layout, finding #1 cylinder

MAF or MAP sensor

Oxygen sensors, How they work, How to change, How to test

PassLock or Passkey

Thermostat issues

Transmission flush

Serpentine belt diagrams

Window issues, power window motor, replace window regulator, glass adhesive

Sunroof creaking on Buick Allure, LaCrosse, Pontiac Grand Prix, Impala, Monte Carlo

Rick — Tue, 19 Feb 2008 18:15:00 +0000

Owners of 2005 Buick Allure and LaCrosse models and 2004-05 Pontiac Grand Prix, Chevrolet Impala and Monte Carlo models may experience a creaking noise coming from the sunroof. The noise is caused by metal-to-metal contact in the left rear corner of the sunroof opening.

To repair, remove the sunroof module assembly. Next, turn the module over and clean the back side of the 12 rivet heads using an alcohol-based cleaner. Then apply Loctite #290 to the perimeter of the rivet. Allow the loctite to dry for 5 minutes and clean off the excess.

Make sure there is a 1/32-in by 2/4-in gap between the roof reinforcement ring and the outer sheet metal in the upper left rear corner of the sun roof and then reinstall the sunroof module.

Alldatadiy.com

eautorepair.net

Both Alldata and Eautorepair offer professional grade shop manuals at a price you can afford. Check them out!.

Hover your mouse over the REPAIR ARTICLES tab at the top of the page. The click on DIAGNOSTICS to search by SYMPTOM, TROUBLE CODE, or read TECH TIPS on how to diagnose a problem

Click on MAKE an MODEL to see all the articles I’ve written for your vehicle
Click on REPAIR TOPICS to read individual articles written for specific automotive systems

If you’ve had your car scanned and know the trouble code go to TROUBLE CODES

Here are some quick links to speed up your research

Click on the link below for speedy navigation:

ABS issues, how to bleed ABS brakes

Airbag issues or SRS light on

Alternator issues or how to test

Belt diagram or serpentine belt issues

Blower motor

Blower motor resistor

Brakes, brake issues, what kind of brake parts to buy, ABS issues

Car Alarms or Antitheft systems

Cooling system, Water pump, What type of coolant to use

Engine flush

Firing order, cylinder layout, finding #1 cylinder

MAF or MAP sensor

Oxygen sensors, How they work, How to change, How to test

PassLock or Passkey

Thermostat issues

Transmission flush

Serpentine belt diagrams

Window issues, power window motor, replace window regulator, glass adhesive

Dead gauges and stall – Buick Allure, LaCrosse, Pontiac Grand Prix

Rick — Tue, 19 Feb 2008 18:06:00 +0000

Owners of 2005 Buick Allure and LaCrosse models and 2004-05 Pontiac Grand Prix models with the 3.8L engine may experience engine stall accompanied by instrument gauges dropping to zero. The speedometer and tachometer may continue to operate normally at this time. In addition, the low fuel indicator light may come on.

The condition is caused by intermittent high resistance between the negative battery cable and the right side frame rail. To repair, remove the cable, clean the surfaces of any corrosion and apply a coating of dielectric grease. The TSB states that it is EXTREMELY important that you use a torque wrench when retightening this cable. The spec is 89-106 INCH lbs.

GM is also recommending a PCM software update. Consult TSB 05-06-037 for details on the software update.

Alldatadiy.com

eautorepair.net

Both Alldata and Eautorepair offer professional grade shop manuals at a price you can afford. Check them out!.

Hover your mouse over the REPAIR ARTICLES tab at the top of the page. The click on DIAGNOSTICS to search by SYMPTOM, TROUBLE CODE, or read TECH TIPS on how to diagnose a problem

Click on MAKE an MODEL to see all the articles I’ve written for your vehicle
Click on REPAIR TOPICS to read individual articles written for specific automotive systems

If you’ve had your car scanned and know the trouble code go to TROUBLE CODES

Here are some quick links to speed up your research

Click on the link below for speedy navigation:

ABS issues, how to bleed ABS brakes

Airbag issues or SRS light on

Alternator issues or how to test

Belt diagram or serpentine belt issues

Blower motor

Blower motor resistor

Brakes, brake issues, what kind of brake parts to buy, ABS issues

Car Alarms or Antitheft systems

Cooling system, Water pump, What type of coolant to use

Engine flush

Firing order, cylinder layout, finding #1 cylinder

MAF or MAP sensor

Oxygen sensors, How they work, How to change, How to test

PassLock or Passkey

Thermostat issues

Transmission flush

Serpentine belt diagrams

Window issues, power window motor, replace window regulator, glass adhesive

P0756 Transmission Code — GM Vehicles

Rick — Wed, 02 Jan 2008 03:57:00 +0000

GM has issued a TSB # 01-07-30-036C to cover all 2001-05 passenger cars and light duty trucks equipped with the 4L60-E or 4L65-E transmission. If the vehicle shows trouble code P0756, it’s a sign of a mechanical failure, not a problem an electrical connector. GM says that a small orifice on the top of the spacer plate can get clogged with debris and cause this trouble code. The repair involves removing the valve body spacer plate and inspecting orifice #29. The code can also be caused by a cracked, broken, or leaking 2-3 shift solenoid. A stuck or hung-up 2-3 shift valve could also bring up this code. If the vehicle is still in warranty, it will be covered. Otherwise, you will have to discuss the cost of repair with your dealer to see if GM is willing to pay for it as a goodwill gesture.

Alldatadiy.com

eautorepair.net

Both Alldata and Eautorepair offer professional grade shop manuals at a price you can afford. Check them out!.

Hover your mouse over the REPAIR ARTICLES tab at the top of the page. The click on DIAGNOSTICS to search by SYMPTOM, TROUBLE CODE, or read TECH TIPS on how to diagnose a problem

Click on MAKE an MODEL to see all the articles I’ve written for your vehicle
Click on REPAIR TOPICS to read individual articles written for specific automotive systems

If you’ve had your car scanned and know the trouble code go to TROUBLE CODES

Here are some quick links to speed up your research

Click on the link below for speedy navigation:

ABS issues, how to bleed ABS brakes

Airbag issues or SRS light on

Alternator issues or how to test

Belt diagram or serpentine belt issues

Blower motor

Blower motor resistor

Brakes, brake issues, what kind of brake parts to buy, ABS issues

Car Alarms or Antitheft systems

Cooling system, Water pump, What type of coolant to use

Engine flush

Firing order, cylinder layout, finding #1 cylinder

MAF or MAP sensor

Oxygen sensors, How they work, How to change, How to test

PassLock or Passkey

Thermostat issues

Transmission flush

Serpentine belt diagrams

Window issues, power window motor, replace window regulator, glass adhesive

Low coolant level light on, but coolant level is fine – GM vehicles

Rick — Sat, 16 Jun 2007 04:38:00 +0000

Your low coolant light goes on and you’ve checked the coolant level. It’s right on the money. Suspecting a faulty sensor, you decide to replace it. STOP. If your vehicle has the 3.1 or 3.4 engine and you’ve had the intake manifold gaskets replaced, or if you’ve added sealer to the system, you may have contamination on the sensor. To confirm that this is the problem, remove the sensor and clean it with a wire brush. Then sand with emory cloth. The sensor should be shiny. Reinstall and see if the problem goes away. If it does, you will have to flush the cooling system to get rid of the contamination. Or, clean the sensor when it gets contaminated.

Alldatadiy.com

eautorepair.net

Both Alldata and Eautorepair offer professional grade shop manuals at a price you can afford. Check them out!.

Hover your mouse over the REPAIR ARTICLES tab at the top of the page. The click on DIAGNOSTICS to search by SYMPTOM, TROUBLE CODE, or read TECH TIPS on how to diagnose a problem

Click on MAKE an MODEL to see all the articles I’ve written for your vehicle
Click on REPAIR TOPICS to read individual articles written for specific automotive systems

If you’ve had your car scanned and know the trouble code go to TROUBLE CODES

Here are some quick links to speed up your research

Click on the link below for speedy navigation:

ABS issues, how to bleed ABS brakes

Airbag issues or SRS light on

Alternator issues or how to test

Belt diagram or serpentine belt issues

Blower motor

Blower motor resistor

Brakes, brake issues, what kind of brake parts to buy, ABS issues

Car Alarms or Antitheft systems

Cooling system, Water pump, What type of coolant to use