The ESC module uses the Pulse-Width Modulation (PWM) method in order to control each shock absorber solenoid. Switching the voltage ON and OFF at each shock absorber solenoid, or pulse width modulating, limits the amount of current supplied to that particular solenoid. The ESC module periodically commands each shock absorber to an set PWM duty cycle in order to override the normal PWM command. During this set PWM duty cycle, the ESC module is able to perform a diagnostic test on each shock absorber solenoid, and can determine if a malfunction is present. The ESC module is only able to detect certain malfunctions during a given state (ON or OFF). In order to test for the conditions that set a DTC C1715, the ESC module must first command the RF solenoid ON. If a high voltage level is detected in the RF solenoid drive circuit during the ON state, the test is again repeated. If the ESC module determines that the voltage levels detected in both tests are higher than expected, a malfunction is present and a DTC will set.
The ESC module detects a high voltage level (short to voltage) on the RF solenoid drive circuit during two diagnostic tests performed.
• | Stores a DTC C1715 in the ESC memory. |
• | Commands 0% PWM duty cycle in order to disable the RF solenoid. |
• | Sends a message to the IPC to display the SERVICE RIDE CONTROL message. |
• | The ESC module no longer detects a high voltage level (short to voltage) on the RF solenoid drive circuit during a diagnostic test. |
• | A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present. |
• | Use the IPC clearing DTC feature. |
• | Using a scan tool. |
• | The following conditions may cause an intermittent malfunction to occur: |
- | There is an intermittent short to voltage on the RF solenoid drive circuit. |
- | The RF solenoid drive and supply circuits are intermittently shorted together. |
- | There is a RF shock absorber solenoid low resistance, internal short, or short to voltage condition. |
• | If the conditions for a DTC C1715 are current, the ESC module will disable the RF solenoid (commanding 0% duty cycle) and the vehicle will experience a soft ride condition on the RF side of the vehicle. |
• | If the DTC is a history DTC, the problem may be intermittent. Using a scan tool, cycle the RF shock absorber solenoid while moving the wiring and the connectors. This can often cause the malfunction to occur. |
The numbers below refer to the step numbers on the diagnostic table:
This step measures the resistance value of the RF shock absorber solenoid.
This step checks for a short to voltage in the RF shock absorber solenoid.
This step checks for a short to voltage on CKT 1117.
This step checks for a short between CKT 1117 and CKT 1116.
This step checks for an intermittent malfunction and requests a thorough inspection of the related RF shock absorber circuit wiring and connectors.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Was the RTD Diagnostic System Check performed? | -- | ||
Is the resistance within the specified value? | 9.5-15.5 ohms | |||
Is the voltage indicated over the specified value? | 1.0 V | |||
Is the voltage indicated over the specified value? | 1.0 V | |||
Is there continuity? | -- | |||
Check the RF shock absorber solenoid circuit for an intermittent malfunction. Refer to Diagnostic Aids. Was an intermittent malfunction found and repaired? | -- | |||
7 | Locate and repair the short to voltage in CKT 1117. Is the circuit repair complete? | -- | -- | |
8 | Locate and repair the short between CKT 1117 and CKT 1116. Is the circuit repair complete? | -- | -- | |
9 | Replace the RF shock absorber. Refer to Shock Absorber Replacement in Front Suspension. Is the repair complete? | -- | -- | |
10 |
Is DTC C1715 current? | -- | System OK | |
11 | Replace the ESC module. Refer to Electronic Suspension Control Module Replacement . Is the repair complete? | -- | -- | |
12 |
Is the repair complete? | -- | -- |