4918-Switch Over Valve Control Circuit Performance-Self Test Failure: Testing

WARNING: This page is about a different car, the 2009 Dodge Sprinter. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR A DTC 4918-SWITCH OVER VALVE CONTROL CIRCUIT PERFORMANCE-SELF TEST FAILURE
1. Turn the ignition on.
2. With the scan tool, read and record DTCs.
3. With the scan tool, read and record Freeze Frame information.
4. With the scan tool, erase DTCs.
5. Start the engine.
6. With the scan tool look at the Brake Switch Signal.
7. Apply the brakes on and off while checking for a Brake Switch Signal change. If excessive travel occurs before switch engages adjust brake switch before continuing.
  Does the scan tool display: 4918-SWITCH OVER VALVE CONTROL CIRCUIT PERFORMANCE-SELF TEST FAILURE?
  
  Yes
  - Go to step 2
  No
  - Perform ABS-INTERMITTENT CONDITION diagnostic procedure. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .
CHECK BRAKE PRESSURE SENSOR
1. Start the engine.
2. With the scan tool look at Pressure Sensor Signal and the Brake Switch Signal.
3. With the brakes not applied the Pressure Sensor should read ± 12 bar (174 psi).
4. Apply the brakes the Pressure Sensor should read above 12 bar (174 psi).
  Did Brake Pressure Sensor increase above 12 bar (174 psi)?
  
  Yes
  - Replace the Integrated Control Unit in accordance with the Service Information.
  - Perform ABS VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .
  No
  - Go to step 3
CHECK FOR AIR IN BRAKE SYSTEM
NOTE: Before continuing the brake system must be bled to verify there is no air in the brake system.
1. Turn ignition off.
2. Bleed brake system.
  Was there any air in the brake system?
  
  Yes
  - Repair as needed.
  - Perform ABS VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .
  No
  - Replace the Integrated Control Unit in accordance with the Service Information.
  - Perform ABS VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure .