Diagnostic Test

WARNING: This page is about a different variant/trim than selected.

CHECK FOR AN ACTIVE DTC
1. Start the engine and test drive the vehicle.
2. Drive the vehicle at a steady speed between 60 km/h (37.3 mph) and 120 km/h (74.6 mph) long enough for MDS mode to become active.
3. With the scan tool, read DTCs and record on the repair order.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK FOR OTHER DTCS
1. Refer to the recorded DTCs.
  Are there any other MDS DTCs or oil pressure system related DTCs active or pending?
  
  Yes
  - Perform the applicable diagnostic procedure(s) before continuing with this test procedure. Refer to DTC INDEX .
  No
  - Go To 3
CHECK OIL PRESSURE TO THE MDS SYSTEM WITH THE SCAN TOOL
1. Start the engine and test drive the vehicle.
2. Drive the vehicle at a steady speed between 60 km/h (37.3 mph) and 120 km/h (74.6 mph) long enough for MDS mode to become active.
3. With the scan tool, observe the oil pressure reading for the MDS Oil Pressure Sensor during operation.
  NOTE:
  The MDS System requires at least 17.4 psi (120 kPa) for the lifters to fully deactivate and the system to operate properly.
  
  Is the MDS System Oil Pressure consistently above the minimum pressure listed above?
  
  Yes
  - Go To 9
  No
  - Go To 4
CHECK THE ENGINE OIL LEVEL AND CONDITION
1. Turn the ignition off.
2. Check the engine oil for the following items. Failure to do so may lead to misdiagnosis.
  - LOW ENGINE OIL LEVEL
  - AERATED ENGINE OIL
  - INCORRECT ENGINE OIL FILTER (DOES NOT MEET OEM SPECIFICATIONS)
  - DETERIORATED OR DIRTY OIL
  - CONTAMINATED ENGINE OIL
  - INCORRECT ENGINE OIL VISCOSITY
  Were any of the above conditions present?
  
  Yes
  - Repair the engine oiling or mechanical condition (i.e. improper oil drain back, oil sludge, damaged oil pump, pick-up tube or seal, etc.).
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK OIL PRESSURE TO THE MDS SYSTEM WITH A GAUGE
1. Remove the MDS Oil Pressure Sensor. Install a mechanical oil pressure gauge in place of the pressure sensor.
2. Start the engine. Raise the engine speed above 1500 rpm and monitor the reading on the oil pressure gauge.
  Is the MDS System Oil Pressure consistently above the minimum pressure?
  
  Yes
  - Go To 9
  No
  - Go To 6
CHECK FOR THE OIL PRESSURE RELIEF VALVE STUCK OPEN
1. Turn the ignition off.
2. Block the pressure relief port or line, or replace the Pressure Relief Valve in accordance with the Service Information.
3. Start the engine, raise the engine speed to above 1500 rpm and recheck the pressure to the MDS System.
4. Check for a restriction in the oil passages to the solenoids and from the solenoids to the lifters.
  Is the MDS System Oil Pressure consistently above the minimum pressure?
  
  Yes
  - If the port or line were blocked off, replace the Pressure Relief Valve in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 7
CHECK THE OIL PRESSURE IN THE LOWER ENGINE BLOCK
1. Turn the ignition off.
2. Remove the oil pressure gauge.
3. Remove the EOP Sensor located near the Oil Filter.
4. Install the mechanical oil pressure gauge in place of the EOP Sensor.
5. Start the engine and check the oil pressure reading. Compare the reading to the specification in the Service Information.
  Does the oil pressure meet specifications?
  
  Yes
  - Go To 8
  No
  - Repair the cause of the low oil pressure condition.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
REPLACE THE CYLINDER DEACTIVATION BOOST PUMP AND RETEST FOR DTC
1. Turn the ignition off.
2. Replace the Cylinder Deactivation Boost Pump in accordance with the Service Information.
3. Connect the Cylinder Deactivation Boost Pump and PCM harness connectors.
4. Turn the ignition on.
5. With the scan tool, erase DTCs.
6. Using the Freeze Frame Data or When Monitored Conditions above, operate the vehicle within the conditions that set the DTC.
  NOTE:
  Drive the vehicle at a steady speed between 60 km/h (37.3 mph) and 120 km/h (74.6 mph) long enough for MDS mode to become active.
7. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 9
  No
  - Replacing the Cylinder Deactivation Boost Pump repaired the fault.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE OIL PASSAGES FOR RESTRICTIONS
1. Turn the ignition off.
2. Remove the Intake Manifold in accordance with the Service Information.
3. Remove the MDS Intake and Exhaust.
4. Remove the Bank 1 Cylinder Head in accordance with the Service Information. Refer to CYLINDER HEAD, REMOVAL AND INSTALLATION .
5. Remove the lifters from the bank 1 cylinders.
6. Check for a restriction in the oil passages to the solenoids and from the solenoids to the lifters.
  Are the passages blocked?
  
  Yes
  - Clean the oil passages as necessary. If the entire engine is restricted disassembly of the entire engine block may be necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace the lifters if no other possible causes remain.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .