Circuit Description
Shock absorber solenoid voltage is supplied to the ESC module through the RTD relay circuit. The ESC module controls the RTD relay by grounding the RTD relay control circuit. This closes the relay contacts providing each shock absorber solenoid with supply voltage through the ESC module's internal solenoid supply circuitry. Each individual solenoid control then controls the operation of the corresponding shock absorber. The ESC module monitors the RTD relay control/solenoid supply circuits for any malfunction conditions.
Conditions for Setting the DTC
| • | The ESC module detects low voltage (an open or a short to ground) on the RTD relay control circuit. |
| • | Detection for this DTC can only be accomplished during the OFF (relay not applied) state. |
Action Taken When the DTC Sets
| • | Stores a DTC C0691 in the ESC memory. |
| • | Commands 0% PWM duty cycle in order to disable all four solenoids. |
| • | Sends a message to the IPC to display the SERVICE RIDE CONTROL and the SHOCKS INOPERATIVE messages. |
| • | Sends a message to the PCM to limit the speed. The PCM then sends a massage to the IPC to display the MAXIMUM SPEED 129 km/h (80 mph) message. |
Conditions for Clearing the DTC
| • | The ignition must be cycled before this DTC can change from current to history even if the malfunction is no longer present. |
| • | The ESC module no longer detects low voltage (an open or a short to ground) on the RTD relay control circuit with the relay OFF. |
| • | A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present. |
| • | The IPC clearing DTCs feature. |
| • | Using a scan tool. |
Diagnostic Aids
| • | The following conditions may cause an intermittent malfunction: |
| - | An open or a short to ground on the RTD relay control circuit. |
| - | An open RTD relay coil or high resistance condition. |
| - | An open RTD relay fuse #7. |
| - | A short to ground on any shock absorber solenoid supply circuit. |
| - |
| • | The RTD relay may be installed in the underhood electrical center in two directions and still function properly. Refer to Power Distribution Schematics Power Distribution Schematics in Wiring Systems for electrical center identification. |
| • | The RTD relay provides supply voltage to all four shock absorber solenoids. Therefore, multiple shock absorber solenoid open or short to ground DTCs may also be stored along with a DTC C0691. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
-
Tests for voltage at the coil side of the RTD Damper Control relay.
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Verifies that the ESC module is providing ground to the RTD Damper Control relay.
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Tests if ground is constantly being applied to the RTD Damper Control relay.
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Tests for an open in the RTD Damper Control circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the RTD Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check |
Does the test lamp illuminate? | -- | Go to Step 3 | Go to Step 9 | |
Does the test lamp turn ON and OFF when the ignition is cycled? | -- | Go to Step 7 | Go to Step 4 | |
Does the test lamp remain illuminated when the ignition is turned ON and OFF? | -- | Go to Step 6 | Go to Step 5 | |
Test the control circuit of the RTD Damper Control relay for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 8 | |
6 | Test the control circuit of the RTD Damper Control relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 8 |
7 | Inspect for poor connections at the RTD Damper Control relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 10 |
8 | Inspect for poor connections at the harness connector of the ESC module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 11 |
9 | Repair the coil side feed circuit of the RTD Damper Control relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 12 | -- |
10 | Replace the RTD Damper Control relay. Did you complete the replacement? | -- | Go to Step 12 | -- |
11 | Replace the ESC module. Refer to Electronic Suspension Control Module Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- |
12 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
