Last Modified: 11-29-2007 1.6 U
Service Category: Suspension Section: Suspension Control System
Model Year: 2008 Model: Sequoia Doc ID: RM000001N9L009X
Title: SUSPENSION CONTROL: AIR SUSPENSION SYSTEM (w/o AVS): FAIL-SAFE CHART (2008 Sequoia)

FAIL-SAFE CHART

1. FAIL-SAFE FUNCTION

(a) When an air suspension system malfunction is detected under normal control operation, the suspension control ECU will suspend the switch control of the height control operation.

DTC No.

Malfunction

Fail-Safe

Fail-Safe Deactivation Condition

C1713

C1714

Height control sensor circuit

  • If there is an error on only 1 side, the system continues vehicle height control.
  • If errors occur on both sides, the system interrupts vehicle height control.

Return to normal condition.

C1745

Exhaust solenoid valve circuit

  • Auto mode:

    The system sets the target vehicle height to normal, performs vehicle height ascent control, and interrupts control.

  • Manual mode:

    The system accepts a switch operation for ascent, provided that the vehicle height is below normal.

Return to normal condition.

C1746

Gate solenoid valve circuit

Interrupts vehicle height control.

Return to normal condition.

C1747

Leveling solenoid valve circuit

Interrupts vehicle height control.

Return to normal condition.

C1751

AIR SUS relay circuit

  • Auto mode:

    The system sets the target vehicle height to normal, performs vehicle height descent control, and interrupts control.

  • Manual mode:

    The system accepts a switch operation for descent, provided that the vehicle height is above normal.

Return to normal condition.

C1752

Lock in height control compressor motor

  • Auto mode:

    The system sets the target vehicle height to normal, performs vehicle height descent control, and interrupts control.

  • Manual mode:

    The system accepts a switch operation for descent, provided that the vehicle height is above normal.

After interrupting for 70 minutes, restart the control.

C1761

Powered continuously or powered excessively in height control compressor motor

  • Auto mode:

    Powered continuously the first time: When the target vehicle speed is set to normal or HI, and the vehicle height is higher than the target, the system performs vehicle height descent control and interrupts control.

    Powered continuously the second time: The system sets the target vehicle height to normal, effects vehicle height descent control, and interrupts control.

  • Manual mode:

    When the compressor motor is powered continuously both the first and second times, the system accepts a switch operation for descent, provided that the vehicle height is above normal.

After interrupting for 70 minutes, restart the control.

C1762

Powered continuously or powered excessively in exhaust solenoid valve

  • Auto mode:

    The system sets the target vehicle height to normal, performs vehicle height ascent control, and interrupts control.

  • Manual mode:

    The system accepts a switch operation for ascent, provided that the vehicle height is below normal.

Return to normal condition.

C1781

Suspension control ECU

Interrupts vehicle height control.

Return to normal condition.

C1782

Power voltage dropped

The system interrupts vehicle height control only when there is an error in the +B power source.

Return to normal condition.

C1783

Vehicle speed sensor circuit

Continues vehicle height control.

Return to normal condition.

U0100

CAN communication system

Continues vehicle height control.

Return to normal condition.

U0122

CAN communication system

Continues vehicle height control.

Return to normal condition.