Rick's Free Auto Repair Advice » Suburban

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!.

Rear Brakes – Uneven brake pad wear, noise, on vehicles with rear disk brakes

Rick — Sun, 28 Aug 2011 17:43:19 +0000

Rear disk brakes are exposed to the same road debris, salt, snow, rain, and heat as front brakes. But because they do only 20% of the braking, they don’t get worn as quickly. That leaves them especially vulnerable to the elements. Since the pads don’t wear as quickly, the caliper doesn’t slide on the caliper pins nearly as far, so caliper pin rusting is far more common. This is especially true in 2000-06 Chevrolet Silverado, Avalanche, and Suburban 1500 trucks.

Every time a caliper slides on the pins, air is either expelled or sucked in. Some manufacturers install a rubber cup over the air breathing hole to allow air to flow but keep out water and road debris. In the Chevrolet design, GM drilled pin holes in the bracket and covered them with rubber bushings. Unfortunately, those rubber bushing aren’t doing the job and the rear caliper pins are rusting and seizing in the bracket. When that happens, the caliper can’t slide and applies braking pressure to only the inboard pad. The result is uneven braking, noise, vibration, and loss of stopping power.

Even though this is a problem on GM trucks, it can happen to any vehicle. I’ve seen caliper pins so frozen in the bracket that the only option is to replace the entire mounting bracket. In fact, this is happening so often that rebuilders are now selling rebuilt brackets

Buy a rebuilt caliper bracket to correct rusted and seized caliper pins

so you don’t have to buy a complete caliper.

One way to avoid this problem is to service the rear calipers about once a year. Retract the rear caliper piston slightly with a special tool (see below). Then remove the caliper. Grease the slide pins with Permatex synthetic brake grease and reinsert the caliper pins. Also apply the grease to the abutment areas where the pads slide

Alldatadiy.com

eautorepair.net

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

GM vehicles with B0071 or B0081 trouble codes.

Rick — Mon, 18 Jul 2011 02:02:52 +0000

If you own one of the vehicles listed below and see a lit SRS (supplemental restraint system) light on your dash, you may have one or both of these trouble codes: B0071 or B0081. Both codes relate to a problem in the Sensing and Diagnostics module. Don’t start replacing air bad components like the clock spring or the module. The problem is most likely the result of a defective seat belt tensioner sensor located in the passenger side seat belt buckle. Contact the dealer for the updated sensor and install it. That should clear the code.

2005-07 Buick Terrazas
2005-09 Chevrolet Uplander, Pontiac Montana
2006-07 Chevrolet Impala
2006-10 Buick Lucerne, Cadillac DTS, Chevrolet HHR, Hummer H3s
2207-10 Cadillac Escalade, ESZ and EXT, Chevrolet Avalanche, Cobalt, Silverado, Suburban, Tahoe, GMC Canyon, Sierra, Yukon, Yukon Denali, Yukon XL, Pontiac G5
2009-10 Hummer H3Ts

Alldatadiy.com

eautorepair.net

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

Turn Signals Problems on Malibu, Impala, Alero, Cutlass, Grand Am, Monte Carlo, Saturn Vue, Chevy S Trucks, Chevy T Trucks, Corvette

Rick — Sun, 13 Mar 2011 18:14:29 +0000

Turn Signals Problems on Malibu, Impala, Alero, Cutlass, Grand Am, Monte Carlo, Saturn Vue, Chevy S Trucks, Chevy T Trucks, Corvette

The GM vehicles above all seem to have a common problem with turn signals. The problem may show up as the following symptoms:

No turn signal operation
Rapid flash even though no bulbs are burned out
Flasher clicks even though turn signal isn’t on
Intermittent turn signal or flasher operation

The source of the problem is usually a faulty Hazard Warning Switch. Yes, you read that correctly. All turn signal operations flow through that switch and it seems GM may have under-engineered the electrical contacts in that switch. Some shops report that even after swapping out the switch, the problem remains and they must replace the entire turn signal mechanism (called the Multifunction Switch). However, dealers report extremely high sales of these Hazard Warning Switches. The dealer list price on the Hazard Switch is about $30. However, Dorman Products makes aftermarket replacements that are half the price of the GM part and are a direct fit for the factory switch. But, if you shop on Amazon you may find AC Delco parts (made by GM) for the same price as Dorman.
To replace the switch you’ll have to remove the bezels and trim panels. I suggest a subscription to Alldata because they show much better interior trim removal diagrams than eautorepair.net.
I’m listing some applications, part numbers, and links. But please double check before you buy to make the part is for your vehicle

1997-2005 Chevrolet Malibu

2000-2005 Chevrolet Impala

1999-2004 Oldsmobile Alero and Cutlass

1999-2005 Pontiac Grand Am

2000-2005 Chevrolet Monte Carlo

1997-2004 Corvette

Alldatadiy.com

eautorepair.net

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

ABS light on GM vehicles

Rick — Fri, 16 Apr 2010 17:17:57 +0000

GM has issued a TSB #04-05-025-002A covering the following vehicles:
2004 Buick Rainier
2002-04 Cadillac Escalade, Escalade EXT
2003-04 Chevrolet Silverado
2000-04 Chevrolet Suburban, Tahoe
2003-04 Chevrolet Avalanche, Trailblazer
2003-04 Chevrolet SSR
1999-04 GMC Sierra
2000-04 GMC Yukon, Yukon Denali, Yukon XL
2002-04 GMC Envoy
2004 GMC Envoy XUV
2002-2004 Oldsmobile Bravada

The problem shows up as a glowing ABS light and trouble coded C0265, C0201, U1041 and a loss of communication with the brake module (EBCM). The TSB warns dealers NOT to replace the EBCM. The problem is a bad ground. Refer to a wiring diagram to find the grounding location for your vehicle. Then clean the ground area and spray it with rubberized undercoating.

For midsized utility vehicles, find the location of ground #304
For Chevrolet SSR, find the location for ground #400
For full-size trucks and utilities, find the location for ground #110

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

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

Remove stuck transfer case fill plugs, GM vehicles

Rick — Mon, 12 Oct 2009 17:56:40 +0000

GM has issued a TSB #99-04-21-001 to discuss methods to remove stuck drain/fill plugs. The TSB applies to 1998-99 Chevrolet and GMC K1-1 Suburban, Utility Models, 1998-99 Oldsmobile Bravada with NOV136 or 246 transfer case.

The drain plugs in these transfer cases are made from aluminum and have a ¼” square drive recess. The user inserts the male end of a standard ¼” square drive extension into the plug to remove it. If too much torque is applied during installation, the threads on the plug may gall and permanently seize, making removal difficult.

If you cannot remove the plug, you must heat the area with a heat gun. As a safety precaution, you MUST clean all oil and grease from the area to prevent a fire. Do NOT use a torch for this procedure. Use only an electric heat gun and follow the procedure below.

1) Apply heat to the case around the plug for 1-2 minutes. Do NOT apply heat directly on the plug itself. Use only enough heat to loosen the plug.

2) If you plan to replace the plug due to thread damage or rounding of the square recess, DO NOT use a steel or brass replacement plug. These metals are dissimilar and will react with the magnesium case, making future removal even MORE difficult.

3) Replacement plugs are available from the dealer. The part number is 15032997.

4) Torque the new plug to 15ft/lbs. That’s NOT a lot of torque, so don’t get carried away 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