C1744

CIRCUIT DESCRIPTION
The CVRSS module monitors a lift/dive signal at the Powertrain Control Module (PCM). Under normal conditions, the CVRSS module supplies a 5 volt reference voltage to the PCM. The PCM grounds this circuit when the vehicle is accelerating rapidly (LIFT) or braking hard (DIVE). When the lift/dive signal goes low (approximately 0 volts), the CVRSS module commands all four CVRSS dampers to a FIRM condition.

CONDITIONS FOR SETTING THE DTC
^ The DTC is set when the CVRSS module does not sense the low-to-high transition on the lift/dive line within 31 seconds after the ignition is turned ON.
^ The DTC turns HISTORY when the CVRSS module senses the low-to-high transition on the lift/dive signal from the PCM during a valid test period.

ACTION TAKEN WHEN THE DTC SETS
^ The CVRSS lift/dive function will be disabled.
^ The vehicle will pitch more during a braking or wide open throttle condition.
^ The SERVICE RIDE CONTROL message will be displayed.

CONDITIONS FOR CLEARING THE MIL/DTC
^ Use the scan tool.
^ Use the On-Board diagnostic CLEAR RSS CODES feature.

DIAGNOSTIC AIDS
As part of the vehicle diagnostic system, the PCM toggles the lift/dive line within 31 seconds after the ignition is turned ON. This allows the CVRSS module to determine if the line is faulted or not. A retry is attempted every four minutes until successful. An intermittent short circuit condition to ground or an open circuit condition in circuit 1490 may cause a random firm/soft ride condition.

TEST DESCRIPTION

IMPORTANT:
^ Do not back probe the sensors, actuators, or any sealed connectors.
^ When all the diagnostics and repairs are complete, clear the DTCs and verify the operation. The number(s) below refer to the step number(s) on the diagnostic table.

2. This step checks to see if the related PCM DTC is set.
3. This step checks for proper voltage at the CVRSS module when the signal is not active.
4. This step manually activates the lift/dive signal (circuit should be at 0 volts).
5. This step saves system information and checks for an open circuit condition in CKT 1490.
11. This step saves system information and checks for short circuit to ground conditions in CKT 1490.
13. This step checks for a short to battery (voltage) condition in CKT 1490.

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DTC C1744 LIFT/DIVE SIGNAL DISCRETE FAULT