The Body Control Module (BCM), or Electronic Suspension Control (ESC) Module, vehicles equipped with Real Time Damping (RTD), provides a pulse width modulated (PWM) supply circuit, and a control circuit to the Electronic Variable Orifice (EVO) solenoid. The supply circuit is used to regulate the current to the solenoid which controls the size of the power steering pump's output fluid orifice, depending on vehicle speed. This results in an increase or decrease in steering effort. The control circuit is used to disable the EVO outputs to provide full steering assist when a malfunction is detected.
NOTE: The BCM/ESC stores the DTCs scan tool data and special functions. However, the scan tool menu to access variable effort steering is located in chassis.
Vehicle speed greater than 8 km/h (5 mph).
EVO solenoid command greater than 5 percent PWM duty cycle.
• | EVO output PWM less than 10 percent duty cycle and EVO output current greater than 260 ma. |
• | EVO output PWM greater than 94 percent duty cycle and EVO output current less than or equal to 360 ma. |
• | DTC C0495 will be stored in memory. |
• | The EVO outputs will be disabled for the remainder of the ignition cycle. |
• | A current DTC will clear on next ignition cycle with no malfunction present. |
• | A history DTC will clear after 100 consecutive malfunction free ignition cycles. |
• | Using the scan tool |
The numbers below refer to the step numbers on the diagnostic table.
Tests the EVO solenoid circuits in there active state using the scan tool.
Tests if the resistance of the EVO solenoid is within the specified range.
Tests if the EVO solenoid supply circuit is shorted to voltage inside the control module.
Tests if the EVO solenoid supply circuit is shorted to voltage
Program the BCM/ESC Module after replacement.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
Schematic Reference: Steering Assist Schematics | ||||
1 |
Important:: If DTC C0501 is also set, perform the diagnostic procedure for C0501 before proceeding. Did you perform the Variable Effort Steering Diagnostic System Check? | -- | Go to Step 2 | |
Does the EVO solenoid turn ON and OFF with each command? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 | |
Does the resistance measure within the specified value? | 11-13 ohms | Go to Step 4 | Go to Step 8 | |
4 | Inspect for poor connections at the EVO solenoid harness connector. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 5 |
Does the test lamp turn on when the ignition is turned ON? | -- | Go to Step 9 | Go to Step 6 | |
Does the test lamp remain on continuously with the ignition ON or OFF? | -- | Go to Step 7 | Go to Step 10 | |
7 | Test the EVO solenoid supply circuit for a short to voltage. Refer to Testing for a Short to Voltage and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9 |
8 | Replace the EVO solenoid. Refer to Power Steering Solenoid Actuator and Discharge Fitting Replacement . Did you complete the replacement? | -- | Go to Step 10 | -- |
Replace the BCM/ESC module. Refer to Body Control Module Replacement in Body Control Systems, or Electronic Suspension Control Module Replacement in Real Time Damping. Did you complete the replacement? | -- | Go to Step 10 | -- | |
10 |
Does the DTC reset? | -- | Go to Step 2 | System OK |