Question about 2003 GMC Yukon XL 1500 SLT

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Air compressor for air ride shocks doesn't come on anymore.

When we first purchased the vehicle, the compressor would come on almost every time that you started it. I read in the manual that they auto level themselves every time you start the vehicle. It's been over a month and the compressor doesn't come on anymore. I'm guessing that I have a bad compressor, but I am not sure.

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6ya6ya
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SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

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Posted on Jan 02, 2017

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  • 116 Answers

SOURCE: Rear Air Shock Problems

springs & air bags in the shock hold the truck level
if they are wet with oil the seal is leaking
replace the shocks

Posted on Dec 13, 2008

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SOURCE: 2004 yukon xl denali self-leveling rear air shocks

There's a lever that connects the driver-side rear shock to the Automatic Level Control module (the air compressor and the ride-height sensor). Disconnect the lever from the shock and rotate it up and hold it. The compressor should kick in when you hold in place after a few seconds. If it doesn't kick in, make sure your fuses and relays are good. Otherwise, you may have a failed ALC module/burned out air compressor (from the shocks being shot). After you replace the shocks (and after you recouped from the heart attack you had when you shelled out $500+ for each shock), replace the ALC module/compressor (it's all one unit), and test it - it should kick on when you rotate the lever up again.

Figure about $350 for the ALC module from your dealer, and make sure the part numbers match! Your truck came with an upgraded ALC module from the 2001-2004 module, which were prone to water damage.

Good luck!

Posted on Dec 30, 2008

emissionwiz
  • 76848 Answers

SOURCE: level ride shocks not working.

have a self test run buy the dealer on the self leveling system, most common causes are the ride height sensor, the air pump is defective or the pump relay is defective.

Posted on Mar 06, 2009

  • 564 Answers

SOURCE: air shock on 03 escalade wont air up. Service ride

may be a bad shock warning these are expensive.or could be a bad ride leveler or height sensor

Posted on Jul 06, 2009

emissionwiz
  • 76848 Answers

SOURCE: 2005 denali service ride control / air suspension pump

the leak almost 100% of the time is in the air bags of the shocks, there are special tools for isolating the individual shocks and seeing if they leak, but as far as the home repair goes u just replace them or have the dealer test them.

Posted on Jul 20, 2009

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1 Answer

Rear air suspension doesn't inflate everytime vehicle is started


My Buick had this problem and we found the pump was worn out. It just would not blow up when trying to run. They wanted a lot of money to replace it and the shocks.so I bought a kit that the air line hooks underneath the license plate Now about once every three months I use my air compressor to pump it up. My old air shocks lost air all the time. My new air shocks stay blowed up for over three months.

May 31, 2017 | Lincoln Navigator Cars & Trucks

1 Answer

Ttrying to fine out where to put the air for the airshock


Vehicles: Cadillacs with ALC-controlled rear shock absorbers

Each rear shock absorber has an ALC (air) port. One may disconnect the ALC air line and try to add air, but this is unlikely to work, since there is no spring-loaded valve to close the port off immediately (like a tire).

A better method for inflating the rear shocks to see if they hold air is to supply 12V DC (from the battery) directly to the ALC system (air) compressor.

Debugging your Cadillac's ALC system can be a challenge. Here are a few basics.

Here's a depiction of the ALC port on the rear shock - found at the end of the ALC air tube.


12_2_2011_12_54_42_am.jpg

Fig. 1 The ALC connection on the rear shock absorber

Here's a close-up of the Cadillac ALC port on the rear shock


12_2_2011_12_59_49_am.jpg

Fig.2 Cadillac ALC air line fitting

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Automatic Level Control System - General Description
Vehicles Without Road Sensing Suspension

The Automatic Level Control (ALC) system automatically adjusts the rear height of the vehicle in response to changes in vehicle loading.

The ALC system consists of a height sensor, an air compressor assembly, an ALC compressor relay, an intake hose and filter, an air tube, and two rear shock absorbers . The air compressor assembly consists of an air compressor and an air dryer mounted on a bracket. The air compressor head is a replaceable part of the air compressor. The (air) exhaust solenoid is a non-replaceable part of the air compressor head.

The compressor is activated when the ignition is on, and weight is added to the vehicle. The exhaust solenoid is connected directly to the battery (+), enabling the system to exhaust with the ignition on or off when excess weight is removed.

Vehicles With Road Sensing Suspension
The Automatic Level Control (ALC) system automatically adjusts the rear height of the vehicle in response to changes in vehicle loading.

The ALC system consists of the CVRSS control module, two CVRSS position sensors, an air compressor assembly, an ALC compressor relay, an intake hose and filter, an air tube, and two rear shock absorbers. The air compressor assembly consists of an air compressor and an air dryer mounted on a bracket. The air compressor head is a replaceable part of the air compressor. The exhaust solenoid is a non-replaceable part of the air compressor head.

The vehicles rear vertical height is measured by the two CVRSS position sensors. These two position sensors convert this rear height measurement into an analog voltage (0 to 5 volts DC) which is read by the CVRSS control module. The control module then determines what action (exhaust, compress, or no action) shall take place. To compress, the CVRSS control module switches the low-side of the ELC compressor relay to ground.

The air compressor is enabled (switched to battery only when the ignition is on. The air compressor is activated when a sufficient amount of weight has been added to the vehicle.

The exhaust solenoid is enabled at all times. The exhaust solenoid is activated when weight is removed from the vehicle.

Automatic Level Control System Operation w/o F45

Raising the Vehicle
When a load is added to the vehicle, the vehicle body moves down causing the sensor actuating arm to rotate upward. The upward arm movement activates an internal timing circuit and, after an initial fixed delay of 17 to 27 seconds, the sensor provides a ground to complete the compressor relay circuit. The 12V (+) circuit to the compressor is then complete and the compressor runs, sending pressurized air to the shock absorbers through the air tubes.

As the shock absorbers inflate, the vehicle body moves upward rotating the actuating arm towards its original position. Once the body reaches its original height, +/- 25 mm (+/- 1 in), the sensor opens the compressor relay circuit, and the compressor is turned off.

Air Compressor Head Relief Sequence
In order to reduce current draw during air compressor starting, the height sensor performs an air compressor head relief sequence before air compressor operation. This sequence reduces the air pressure in the air compressor cylinder during start-up. The air compressor head relief sequence occurs as follows:

Exhaust solenoid is energized.
Air compressor is activated 1.3 seconds after the exhaust solenoid is energized.
Exhaust solenoid is de-energized 0.5 seconds after the air compressor is activated.
Lowering the Vehicle
When a load is removed from the rear of the vehicle, the body rises, causing the sensor actuating arm to rotate downward. This again activates the internal timing circuit. After the initial fixed delay, the sensor provides a ground to complete the exhaust solenoid circuit, energizing the solenoid. Now, air starts exhausting out of the shock absorbers, back through the air dryer and exhaust solenoid valve, and into the atmosphere.

As the vehicle body lowers, the actuating arm rotates to its original position. When the vehicle body reaches its original height, +/- 25 mm (+/- 1 in), the sensor opens the exhaust solenoid circuit, which closes the exhaust solenoid and prevents air from escaping.

Air Replenishment Cycle
The sensor actuating arm position is checked when the ignition is turned on. If the sensor indicates that no height adjustment is needed, an internal timer circuit is activated. After about 35 to 55 seconds, the compressor is turned on for 3 to 5 seconds. This ensures that the shock absorbers are filled with the proper residual pressure. If weight is added to or removed from the vehicle during the time delay, the air replenishment cycle is overridden, and the vehicle rises or lowers after the normal delay.

Automatic Level Control System Operation w/ F45

Raising the Vehicle
When a load is added to the vehicle, the vehicle body moves down causing the sensor actuating arm to rotate upward. The upward arm movement activates an internal timing circuit and, after an initial fixed delay, the CVRSS control module provides a ground to complete the compressor relay circuit. The 12V (+) circuit to the compressor is then complete and the compressor runs, sending pressurized air to the shock absorbers through the air tubes.

As the shock absorbers inflate, the vehicle body moves upward rotating the actuating arm towards its original position. Once the body reaches its original height, +/- 25 mm (+/- 1 in), the compressor relay circuit is opened and the compressor is turned off.

Air Compressor Head Relief Sequence
In order to reduce current draw during air compressor starting, the CVRSS control module performs an air compressor head relief sequence before air compressor operation. This sequence reduces the air pressure in the air compressor cylinder during start-up. The air compressor head relief sequence occurs as follows:

Exhaust solenoid is energized.
Air compressor is activated 1.3 seconds after the exhaust solenoid is energized.
Exhaust solenoid is de-energized 0.5 seconds after the air compressor is activated.

Lowering the Vehicle
When a load is removed from the rear of the vehicle, the body rises, causing the sensor actuating arm to rotate downward. This again activates the internal timing circuit. After the initial fixed delay, the CVRSS control module provides a ground to complete the exhaust solenoid circuit, energizing the solenoid. Now, air starts exhausting out of the shock absorbers, back through the air dryer and exhaust solenoid valve, and into the atmosphere.

As the vehicle body lowers, the actuating arm rotates to its original position. When the vehicle body reaches its original height, +/- 25 mm (+/- 1 in), the exhaust solenoid circuit is opened, which closes the exhaust solenoid and prevents air from escaping.

Air Replenishment Cycle
An air replenishment cycle (ARC) is commanded after each ignition-ON cycle. The purpose of the ARC is to ensure that the ALC system is operating at or above minimum air pressure (residual air pressure). The ARC occurs as follows:

The EXHAUST SOLENOID IS ENERGIZED 20 seconds after the ignition has been turned on.
The AIR COMPRESSOR IS ACTIVATED 1.3 seconds after the exhaust solenoid is energized.
The EXHAUST SOLENOID IS DE-ENERGIZED 0.5 seconds after the air compressor is activated.
The AIR COMPRESSOR IS DEACTIVATED 3.2 seconds after the exhaust solenoid is de-energized.

Dec 01, 2011 | 1998 Cadillac DeVille

2 Answers

What is the differnce of a Lt autoride and a Lt


the lt autoride has self adjusting shocks, and the regular lt doesn't. if you look the autoride has airlines going to the shocks.

Nov 08, 2010 | 2002 Chevrolet Tahoe

2 Answers

Lift sensor for rear of 1988 Deville


To begin with, check the "ride level" fuse and make sure that the ride level compressor does work, and you should be able to hear that the ride level compressor is working when the ride level system is leveling the vehicle.

The ride level system uses an air compressor and either an air type of shocks or a type of air billow to raise and lower the vehicle, there is an adjustment to set the ride height and it is located under the vehicle and there is a control lever or rod that should be connected between the rear axle and a switch that is mounted on the body of the vehicle, and there will be an adjustment slot in the control lever between the switch and the body, and that is how you would adjust the ride level height, but be sure that the vehicle can not drop any further down if someone is under the vehicle trying to adjust the ride height.

However, you might find that the control lever to the ride level has fallen off from the switch on the body or it has come loose from the rear axle, and it is just hanging there not operating the switch on the body that controls the the ride level compressor, or there might be a blown out air shock or billow, or you might find that an air line from the compressor is leaking and the ride level compressor will just run continuously until it blows out the fuse, and if that is the case you might also find out that the air compressor has burned out from running continuously.

I hope that this information will help you to solve your ride level problem.

Jun 04, 2010 | 1988 Cadillac Sedan DeVille

1 Answer

Electronic level control not working right in a 1999 cadillace deville, what can i do to fix it?


To begin with, check the "ride level" fuse and make sure that the ride level compressor does work, and you should be able to hear that the ride level compressor is working when the ride level system is leveling the vehicle.

The ride level system uses an air compressor and either an air type of shocks or a type of air billow to raise and lower the vehicle, there is an adjustment to set the ride height and it is located under the vehicle and there is a control lever or rod that should be connected between the rear axle and a switch that is mounted on the body of the vehicle, and there will be an adjustment slot in the control lever between the switch and the body, and that is how you would adjust the ride level height, but be sure that the vehicle can not drop any further down if someone is under the vehicle trying to adjust the ride height.

However, you might find that the control lever to the ride level has fallen off from the switch on the body or it has come loose from the rear axle, and it is just hanging there not operating the switch on the body that controls the the ride level compressor, or there might be a blown out air shock or billow, or you might find that an air line from the compressor is leaking and the ride level compressor will just run continuously until it blows out the fuse, and if that is the case you might also find out that the air compressor has burned out from running continuously.

May 23, 2010 | 1998 Cadillac DeVille

1 Answer

How do i reset the SERVICE RIDE CONTROL message that comes up every time i turn on my truck once i've made sure the shocks and compressor are in good shape


THIS LIGHT IS ON BECAUSE THERE IS A PROBLEM WITH THE AIR SUSPENSION RIDE CONTROL, IT WILL GO OFF AS SOON AS U REPAIR THAT PROBLEM WHICH IS MOST LIKELY A LEAKING AIR SUSPENSION AIR BAG, THERE IS NO RESET AS THE RIDE CONTROL DOESN''T HAVE A MEMORY AND CAN'T STORE CODES, IT ONLY COMES ON WHEN A PROBLEM IS PRESENT IN REAL TIME.

Mar 19, 2010 | 2003 Cadillac Escalade

1 Answer

I have a 1994 lincoln continental car. Hoe do I replace the suspention drier?


why do you want to replace it? As air is exhausted through it, it dires it out for the next use. it's part of compressor assembly.

1996 cont'l The air suspension system includes the following major components:
  • Air compressor to supply air to the air springs (part of front spring and shock and rear spring and shock absorber assemblies
  • Front spring and shock (3C098) and rear spring and shock absorber (5A965) at each corner of the vehicle
  • Four linear air suspension height sensors (5359): two rear and two front height sensors to maintain the vehicle at the proper ride height; only LH rear height sensor is used for air suspension.
  • Dual-mode front spring and shock and rear shock absorber assemblies with internal actuator.
All system functions are controlled by vehicle dynamics control module (5A919). This control module receives inputs from several different sources. These inputs include:
  • vehicle speed via multiplex communication network
  • ignition switch position
  • door position via multiplex communication network
  • height sensor position
  • air suspension service switch
  • engine rpm via multiplex communication network
  • ride and steering personality settings via multiplex communications network
Communications monitor system operation and allow diagnosis of any concerns that may develop in the system. System monitoring for the driver's use is provided through the instrument panel mounted message center indicator (10D898).
  • Diagnosis communication for the service technician is provided through the data link connector (14489) (DLC) under the instrument panel and Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent.
The message center indicator will display AIR LEVELING DISABLED or CHECK RIDE CONTROL if the suspension system is not turned on or the vehicle dynamics control module detects a concern. If air leveling system disabled is displayed, check that air suspension service switch is in the ON position.
----------------------------------------------------------
Solenoid Valve Vent The vent solenoid valve operates as follows:
  • The vent solenoid valve allows air to escape from the system during venting corrections.
  • The valve is located in the air compressor cylinder head and shares a common electrical connector with the motor.
  • The valve is enclosed in the cylinder head casting, which forms an integral valve housing that allows the valve tip to enter the pressurized side of the system.
  • Air leakage past the valve tip is prevented by an O-ring seal.
  • The vent solenoid valve opens when a corner of the vehicle is high and the vehicle dynamics control module (5A919) determines lowering is required.
  • When the vent solenoid valve is opened, it provides an escape route for pressurized air.
  • However, the vehicle will not lower unless the air spring solenoid valves (5311) are also opened to allow air to leave the springs.
  • Lowering the vehicle corners requires the vehicle dynamics control module to open two solenoid valves, the vent and one air spring solenoid.
  • Air is exhausted from the spring and vents through the compressor air drier (5346).
---------------------------------------------------------------------------------------------
Section 04-05: Suspension, Computer Controlled 1996 Continental Workshop Manual
REMOVAL AND INSTALLATION Air Compressor and Drier Assembly Removal
  1. Turn air suspension service switch OFF.
  1. Disconnect electrical connector located on the air compressor.
  1. Disconnect two air lines from compressor air drier.
  1. Remove three fasteners retaining air compressor and drier assembly to radiator support, frame rail and fender apron.

Dec 22, 2009 | 1994 Lincoln Continental

1 Answer

REPLACED DRYER ON 96 CONT NOW THE BACK WONT AIR UP FRONT DOES


maybe you got dirt in the line to the rear. Here's some background info:

The air suspension system includes the following major components:
  • Air compressor to supply air to the air springs (part of front spring and shock and rear spring and shock absorber assemblies
  • Front spring and shock (3C098) and rear spring and shock absorber (5A965) at each corner of the vehicle
  • Four linear air suspension height sensors (5359): two rear and two front height sensors to maintain the vehicle at the proper ride height; only LH rear height sensor is used for air suspension.
  • Dual-mode front spring and shock and rear shock absorber assemblies with internal actuator.
All system functions are controlled by vehicle dynamics control module (5A919). This control module receives inputs from several different sources. These inputs include:
  • vehicle speed via multiplex communication network
  • ignition switch position
  • door position via multiplex communication network
  • height sensor position
  • air suspension service switch
  • engine rpm via multiplex communication network
  • ride and steering personality settings via multiplex communications network
Communications monitor system operation and allow diagnosis of any concerns that may develop in the system.
  • System monitoring for the driver's use is provided through the instrument panel mounted message center indicator (10D898).
  • Diagnosis communication for the service technician is provided through the data link connector (14489) (DLC) under the instrument panel and Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent.
The message center indicator will display AIR LEVELING DISABLED or CHECK RIDE CONTROL if the suspension system is not turned on or the vehicle dynamics control module detects a concern. If air leveling system disabled is displayed, check that air suspension service switch is in the ON position.
-------------------------------------------------------
Weight Added When weight is added to the vehicle, the air suspension system responds as follows:
  • Air suspension height sensor length is reduced from trim length, sending a "vehicle is low" signal to the vehicle dynamics control module (5A919).
  • To restore vehicle to the trim position, the vehicle dynamics control module turns the compressor on by grounding the compressor relay control Circuit 420 (DB/Y). The relay is ground-side switched.
  • To allow pressurized air to enter the rear spring (5560) and front spring and shock (3C098), the control module opens the solenoid valves (5311).
  • Compressed air flows from the compressor, through the compressor air drier assembly, air lines and solenoid valves into the air springs.
  • As the air springs raise the body height, the air suspension height sensor (5359) increases in length until the preset trim height is reached.
  • The vehicle dynamics control module then turns off the compressor (through the relay) and closes the air spring solenoid valves.
  • ----------------------------------------------------------------------------
  • Weight Removed When weight is removed, the air suspension system responds as follows:
    • Air suspension height sensor length is increased from the trim length, sending a "vehicle is high" signal to the control module (5A919).
    • To restore the vehicle to the trim position, the vehicle dynamics control module opens the vent solenoid valve (located in the compressor assembly) and opens the solenoid valves (5311).
    • Compressed air flows from air springs, through the solenoid valves, air lines, compressor air drier (5346) and out the vent solenoid valve.
    • As the body lowers, the air suspension height sensor length decreases until the preset trim height is reached.
    • The vehicle dynamics control module then closes the vent and solenoid valves.
------------------------------------------------------------------------------
Control Module Power and Ground The vehicle dynamics control module (5A919) is located above the upper luggage compartment trim panel and lower module tray. Module power is provided by Circuit 418 (DG/Y) at Pins 36, 37, 56, 57, 58 and is powered through a Fuse 7 (30A) in power distribution box. Module ground is provided through control module wire harness Pins 6, 39, 40 and 60. The data link connector (14489) (DLC) is located in the passenger compartment under the instrument panel, 300 mm (12 inches) right of the steering column. This connector allows communications between the vehicle dynamics control module and either Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent or Rotunda Service Bay Diagnostics System (SBDS)® 001-00001 or equivalent. When the CHECK RIDE CONTROL message is displayed in the message center indicator (10D898), a system error has been detected by the vehicle dynamics control module and is stored in the control module. This diagnostic trouble code (DTC) will be retained for the next 80 ignition switch cycles. If there is no repeat of the same error during these 80 ignition switch cycles, the control module will erase the DTC. Because of this self-erasing memory, a customer may have had a concern "just a few days ago" that is not retrieved from memory when Diagnostic Test Mode (DTC) "Retrieve/Clear Continuous DTCs" is executed. This must be kept in mind if you must tell customer that no current concern has been found. When the vehicle dynamics control module detects a concern, the air suspension system is disabled for the current ignition cycle. If the condition causing the concern clears up during the current ignition switch cycle, the system will not reactivate. For example, if the customer has severely overloaded the luggage compartment, the system will not be able to trim the vehicle without exceeding the compressor run time. This will generate a DTC that disables the computer controlled suspension system. If the customer then drives the vehicle and unloads the luggage compartment without turning the ignition switch OFF, the system will not adjust for the new load. The customer will experience poor ride quality and the vehicle will not adjust trim.

May 20, 2009 | 1996 Lincoln Continental

3 Answers

Service ride control


The fuse is called RTD 30 amp under the hoodfuse box. That is for the Air Compressor.

Parts.com has the best price for:

Rear Suspension:
Shock W/auto level control - 1500 series

and under
electrical:
then ride control components
then compressor

May 03, 2009 | 2006 GMC Yukon Xl Denali

1 Answer

1990 Oldsmobile Ninety-Eight Regency compressor runs when car is off.


The compressor you refer to is the air suspension compressor. It provides air to adjust the ride height of the vehicle. If you will notice by looking underneath the rear of the vehicle you will notice air adjustable rear shocks, or struts. They have plastic tubing plumbed to the compressor under the hood. There is a ride height sensor for the rear of the vehicle attached from the chasis to the rear differential. Whenever the height of the rear of the car is below the threshold setting of the sensor, the system activates a relay and turns on the compressor to raise the rear of the vehicle above the minimum height specified by the manufacturer. As the vehicle ages the air envelopes of the struts loses structural integrity and seepage, or leakage develops. Some depletion of air is normal, but the compressor power supply is independent of the key position, so the compressor can run, and will run anytime the height falls below the minimum. If the car sets unattended for several days, (or weeks) the compressor can run the battery down while maintaining the minimum height. If the system leaks too much air the compressor can burn-out trying to replenish the system. If you notice the compressor runing for an extended period of time, or running too frequently you should have the system checked for the source of the leakage. (Or you can do it yourself with soapy water and a spray bottle by soaking the air bellows on the shocks or struts, and all the lines and fittings from the shocks to the compressor) If you intend to work underneath a vehicle, service stands are mandatory! DO NOT UNDER ANY CIRCUMSTANCES ATTEMPT UNDER VEHICLE SERVICE WITHOUT PROPER SERVICE STANDS IN PLACE AND STABILITY VERIFIED WITH APPROPRIATE FORCE TO PROVE THE VEHICLE CANNOT BE KNOCKED-OFF THE SERVICE STANDS!

Nov 01, 2008 | 1992 Oldsmobile Ninety Eight Regency

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