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Before replacing any air suspension components, disconnect power to the system by turning off the air suspension switch located in the rh kick panel area to prevent vehicle damage or personal injury. Rear Air Suspension Load Leveling Control Components
Compressor Air Drier Air Suspension Switch Generic Electronic Module (GEM) Powertrain Control Module Air Suspension Control Module
Check Air Suspension Indicator Vehicle Speed Sensor Electronic Steering Sensor Ignition Switch Air Suspension Height Sensor— (Rear)
Rear Air Springs Air Lines Brake Pedal Position (BPP) Switch Electronic Variable Orifice (EVO) Actuator Air Compressor Relay
Air Compressor

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1. Vent the air suspension system. WARNING: DO NOT REMOVE AN AIR SPRING UNDER ANY CIRCUMSTANCES WHEN THERE IS PRESSURE IN THE AIR SPRING. DO NOT REMOVE ANY COMPONENTS SUPPORTING AN AIR SPRING WITHOUT EITHER EXHAUSTING THE AIR OR PROVIDING SUPPORT FOR THE AIR SPRING TO PREVENT VEHICLE DAMAGE OR PERSONAL INJURY . 2. Turn the air suspension switch off. WARNING: BEFORE PERFORMING MAINTENANCE ON ANY AIR SUSPENSION COMPONENTS, DISCONNECT THE POWER TO THE SYSTEM BY TURNING OFF THE AIR SUSPENSION SWITCH LOCATED ON THE LH SIDE OF THE LUGGAGE COMPARTMENT TO PREVENT VEHICLE DAMAGE OR PERSONAL INJURY . 3. Raise and support the vehicle. 4. Remove the rear air spring retainer. 5. Lift the bottom of the air spring off the rear axle. 6. Remove the air spring. 1) Disconnect the electrical connector. 2) Push up on the air line retaining ring and disconnect the air line. 3) Remove the air spring. INSTALLATION To install, reverse the removal procedure. NOTE: To avoid damage to the air spring, do not allow suspension to compress before the spring is inflated. When installing the air line into the solenoid, a minimum of 3 mm (1/8 inch) of line must be inserted for proper operation of the air spring.

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Inflation and Deflation of the Air Suspension System WARNING: Do not remove an air spring under any circumstances when there is pressure in the air spring. Do not remove any components supporting an air spring without either exhausting the air or providing support for the air spring to prevent vehicle damage or personal injury. WARNING: Disconnecting an air line that is connected to the air compressor can cause personal injury or damage to components as high pressure air is vented uncontrolled. 1. Turn the air suspension switch on. 2. Turn the ignition switch to the RUN position. 3. Connect NGS Tester to the data link connector (DLC). 4. Select Air Suspension Control Module under Active Command Mode: ? VENT FRNT to deflate the front down. ? LIFT FRNT to inflate the front up. ? VENT REAR to deflate the rear down. ? LIFT REAR to inflate the rear up. Calibration Front Ride Height Resetting — Clear B2140 DTC 1. Turn the ignition key OFF and turn it back to RUN; exit the vehicle, close all doors and allow the system to vent the vehicle down to kneel height (approximately 30 seconds). 2. Connect New Generation STAR (NGS) Tester to the data link connector (DLC). 3. Select the proper vehicle year, model and engine type. 4. Select 4WAS-AIR SUSP/EVO (4×2 and 4×4) module. 5. Select “Parameter Reset Command (Clear Ride Height) under Active Command Modes” menu, trigger through the warning messages and reset (trigger from OFF to ON): ? NGS version 10.0 — “Front” and “Rear.” ? NGS version 11.0+ — “Front CLR.” 6. Back out the torsion bar adjustment bolt (approximately 40 mm from the bolt head to the bottom surface of the torsion bar adjuster). 7. Deflate the front air shocks by using the NGS “Vent Front” command in “Air Suspension Control” menu (should take about 30 seconds), and jounce the front of the vehicle to fully lower the front of the vehicle. 8. Adjust and measure the vehicle ride height; refer to Section 204-01B. 9. NOTE: Do not save rear ride heights. The air suspension control module has precalibrated values already stored. Refer to Rear Ride Height Mechanical Resetting. Select the “Save Calibration Values (Store Ride Height)” NGS command to calibrate the air suspension control module. Trigger through the warning message(s) and save “FRONT” (trigger from OFF to ON).

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Refer to Engine Controls Schematics MAF, Secondary Air Injection Pump Bypass Solenoid, IAC and Secondary AIR Pump . Circuit Description The AIR pump is used on this vehicle to lower tail pipe emissions on start-up. The powertrain control module (PCM) grounds the AIR pump relay control circuit, which energizes the AIR pump. The PCM also grounds the AIR solenoid valve control circuit, which energizes the AIR solenoid valve. The AIR solenoid valve opens allowing manifold vacuum to open the AIR control valves. The PCM enables both control circuits when AIR system operation is desired. When the AIR system is active, the AIR pump forces fresh air into the exhaust stream in order to accelerate catalyst operation. The AIR control valves replace the conventional check valves. When the AIR system is inactive, the AIR control valves prevent air flow in either direction. DTC P0412 applies to the AIR solenoid control circuit. DTC P0418 applies to the AIR pump relay control circuit. DTC P0410 sets if an air flow problem is detected. The PCM will run two tests using the heated oxygen sensor (HO2S) voltage to diagnose the AIR system. Both tests have two parts. The passive test is performed during regular AIR pump operation. The passive test consists of the following: Passive Test Part 1 When the AIR system is enabled, the PCM monitors the HO2S voltage. If the HO2S voltage goes below a threshold, the PCM interprets this as an indication that the AIR system is operational. Passive Test Part 2 When the AIR system is disabled, the PCM monitors the HO2S voltage. The HO2S voltage should increase above a threshold and switch normally. If both of these tests indicate a pass, no further action is taken. If one of the above tests failed or is inconclusive, the diagnostic will proceed to test two. The active test is performed specifically for diagnostic purposes. Test two consists of the following: Active Test Part 1 During this test the PCM turns the AIR system on during closed loop operation. When the AIR system is activated, the PCM monitors the HO2S voltage. If the AIR system is operating properly, the HO2S voltage should go below a predetermined threshold. Active Test Part 2 The PCM turns the AIR system off. The HO2S voltage should return to above a rich threshold.

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Some vehicles may exhibit a check suspension lamp on with Diagnostic Trouble Codes (DTC’s) B2140 or C2140 even after the Air Suspension switch in the upper RH kick panel has been turned on. This may occur at pre-delivery, following suspension service, or after Air Suspension module replacement. This may be caused by the ride height calibration. ACTION Adjust and/or recalibrate ride height as necessary using the NGS (New Generation Star) Tester. Refer to the following Service Procedure for details. SERVICE PROCEDURE NOTE DURING PDI (PRE-DELIVERY INSPECTION) IF “CK SUSP” LIGHT IS ON, PRIOR TO SENDING TO SERVICE, VERIFY SWITCH IN UPPER RIGHT KICK PANEL IS ON. THIS SWITCH IS TURNED OFF DURING VEHICLE SHIPMENT TO PREVENT MODULE FROM SEEKING TRIM HEIGHT WHILE
SECURED DOWN FOR TRANSPORT.