Diagnostic Test

WARNING: This page is about a different car, the 2014 RAM 1500. However, it is still accessible from the selected car via links, so may be relevant.

ACTIVE DTC
NOTE:
Diagnose and repair any communication or low voltage DTCs before proceeding with this test.
1. Ignition on, engine not running.
2. With the scan tool, select View DTCs.
  NOTE:
  If DTCs P258A, P258C, or P258D are present, perform the Diagnostics for those DTCs before continuing with this one.
  
  Is the DTC Active or Pending at this time?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT DTC .
ENGINE WITH ELECTRIC VACUUM PUMP
1. Verify vehicle is equipped with an Electric Vacuum Pump.
  Is this vehicle equipped with an Electric Vacuum Pump?
  
  Yes
  - Go To 3
  No
  - Go To 11
ELECTRIC VACUUM PUMP
1. Turn the ignition on.
2. With the scan tool actuate the Electronic Vacuum Pump.
  Does the Electric Vacuum Pump run?
  
  Yes
  - Go To 6
  No
  - Go To 4
CHECK THE FUSED B+ CIRCUIT

Fig 1: Checking Fused B+ Circuit
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Remove the EVP Relay from the relay connector in the PDC.
3. Ignition on, engine not running.
4. Using a 12-Volt test light connected to ground, probe the Fused B+ circuit in the EVP Relay harness connector.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 5
  No
  - Replace the PDC in accordance with the service information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
CHECK THE Z906 EVP GROUND CIRCUIT
1. Using a 12-volt test light connected to 12 volts, probe the Z906 EVP Ground circuit at the EVP harness connector.
  Does the test light illuminate brightly?
  
  Yes
  - Replace the Electric Vacuum Pump in accordance with the service information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
  No
  - Repair the Z906 EVP Ground circuit for an open/high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
CHECK FOR PINCHED VACUUM SUPPLY LINE
1. Turn the ignition off.
2. Check the vacuum supply line to brake booster for a pinched, cut or open hose.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
  No
  - Go To 7
VACUUM PRESSURE SIGNAL
1. Start the engine.
2. With the scan tool, view and record the vacuum pressure signal with foot off the brake pedal.
3. With the scan tool, view the vacuum pressure signal while pressing the brake pedal several times.
4. Record the highest value.
  Without the brake pedal applied, was the vacuum pressure signal -40 kPa (12 in. Hg)?
  
  Yes
  - Go To 8
  No
  - Replace the Power Brake Booster in accordance with the service information. Refer to BOOSTER, POWER BRAKE, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
CHECK FOR VACUUM PRESSURE SIGNAL CHANGE
1. Turn the ignition on.
2. Remove the Vacuum Pressure Sensor from the Booster.
3. Connect a vacuum pump to the Vacuum Pressure Sensor.
4. Apply vacuum to the Vacuum Pressure Sensor and watch for signal change.
  Is the voltage signal changing on the scan tool as vacuum is being applied?
  
  Yes
  - Go To 9
  No
  - Replace the Vacuum Pressure Sensor in accordance with the service information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
CHECK BRAKE BOOSTER CHECK VALVE
1. Remove the Brake Booster Check Valve.
2. Apply vacuum to the booster side of the check valve.
  Is the Brake Booster Check Valve holding vacuum?
  
  Yes
  - Go To 10
  No
  - Replace the Power Brake Booster Check Valve in accordance with the service information. Refer to BOOSTER, POWER BRAKE, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
CHECK BRAKE BOOSTER
1. Reinstall the Brake Booster Check Valve.
2. Apply vacuum to the Brake Booster.
  Is the Brake Booster holding vacuum?
  
  Yes
  - Go To 11
  No
  - Replace the Power Brake Booster in accordance with the service information. Refer to BOOSTER, POWER BRAKE, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
ANTI-LOCK BRAKE SYSTEM (ABS)
1. Turn the ignition off to the lock position.
2. Perform any Technical Service Bulletins that may apply.
3. Inspect the related wiring harness. Look for any chafed, pierced, pinched or partially broken wires.
4. Inspect the related wire harness connectors. Look for broken, bent, pushed out or corroded terminals.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
  No
  - Replace the Anti-lock Brake System (ABS) Module in accordance with the service information. Refer to MODULE, ANTI-LOCK BRAKE SYSTEM, REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .