2006 DODGE RAM SRT-10 oil pressure

For a complete wiring diagramRefer to Section 8W.
Theory of Operation
When all criteria has been met, power is supplied to each MDS Solenoid when the engine is making a transition
from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that
coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse,
decoupling the valves and camshaft.
When Monitored:
Transition from 8 to 4 cylinder mode.
Set Condition:
The MDS fails to active and take place for cylinder 1. One trip fault.
Possible Causes
(K451) MDS SOLENOID NO.1 CONTROL SHORT TO GROUND
(K451) MDS SOLENOID NO.1 CONTROL OPEN
(Z42) GROUND CIRCUIT OPEN
INSUFFICIENT OIL PRESSURE ACTING ON THE LIFTER LOCKING PINS
OIL PASSAGES RESTRICTED
LIFTER
MDS SOLENOID NO.1
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

For a complete wiring diagramRefer to Section 8W.
Theory of Operation
When all criteria has been met, power is supplied to each MDS Solenoid when the engine is making a transition
from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that
coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse,
decoupling the valves and camshaft.
When Monitored:
Transition from 8 to 4 cylinder mode.
Set Condition:
The MDS fails to active and take place for cylinder 4. One trip fault.
Possible Causes
(K452) MDS SOLENOID NO.4 CONTROL SHORT TO GROUND
(K452) MDS SOLENOID NO.4 CONTROL OPEN
(Z42) GROUND CIRCUIT OPEN
INSUFFICIENT OIL PRESSURE ACTING ON THE LIFTER LOCKING PINS
OIL PASSAGES RESTRICTED
LIFTER
MDS SOLENOID NO.4
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

For a complete wiring diagramRefer to Section 8W.
Theory of Operation
When all criteria has been met, power is supplied to each MDS Solenoid when the engine is making a transition
from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that
coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse,
decoupling the valves and camshaft.
When Monitored:
Transition from 8 to 4 cylinder mode.
Set Condition:
The MDS fails to active and take place for cylinder 6. One trip fault.
Possible Causes
(K453) MDS SOLENOID NO.6 CONTROL SHORT TO GROUND
(K453) MDS SOLENOID NO.6 CONTROL OPEN
(Z42) GROUND CIRCUIT OPEN
INSUFFICIENT OIL PRESSURE ACTING ON THE LIFTER LOCKING PINS
OIL PASSAGES RESTRICTED
LIFTER
MDS SOLENOID NO.6
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.MDS SOLENOID NO.6
Turn the ignition off.
Gain access to the MDS Solenoid No.6.
Disconnect the MDS Solenoid No.6 harness connector.
Ignition on, engine not running.
Turn off all accessories.
Using a 12-volt test light connected to the (Z42) Ground circuit, probe
the (K453) MDS Solenoid No.6 Control circuit.
With a scan tool, actuate the MDS Solenoid 6.
Does the 12-volt test light flash on and off?
Ye s>>
Go To 7
No>>
Go To 3

For a complete wiring diagramRefer to Section 8W.
Theory of Operation
When all criteria has been met, power is supplied to each MDS Solenoid when the engine is making a transition
from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that
coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse,
decoupling the valves and camshaft.
When Monitored:
Transition from 8 to 4 cylinder mode.
Set Condition:
The MDS fails to active and take place for cylinder 7. One trip fault.
Possible Causes
(K454) MDS SOLENOID NO.7 CONTROL SHORT TO GROUND
(K454) MDS SOLENOID NO.7 CONTROL OPEN
(Z42) GROUND CIRCUIT OPEN
INSUFFICIENT OIL PRESSURE ACTING ON THE LIFTER LOCKING PINS
OIL PASSAGES RESTRICTED
LIFTER
MDS SOLENOID NO.7
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.MDS SOLENOID NO.7
Turn the ignition off.
Gain access to the MDS Solenoid No.7.
Disconnect the MDS Solenoid No.7 harness connector.
Ignition on, engine not running.
Turn off all accessories.
Using a 12-volt test light connected to the (Z904) Ground circuit, probe
the (K454) MDS Solenoid No.7 Control circuit.
With a scan tool, actuate the MDS Solenoid 7.
Does the 12-volt test light flash on and off?
Ye s>>
Go To 7
No>>
Go To 3

P1521–INCORRECT ENGINE OIL TYPE
When Monitored:
Engine Running.
Set Condition:
Using the oil pressure, oil temperature and other vital engine inputs the PCM can determine the engine oil
viscosity. Incorrect viscosity will effect the operation of the MDS by delaying cylinder activation.
Possible Causes
INCORRECT ENGINE OIL TYPE
ENGINE OIL CONTAMINATION
ENGINE OIL
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.ACTIVE DTC
NOTE: Review the customers oil change history. Make sure the customers is using the correct engine oil
viscosity. If the incorrect oil is being used, change the oil, using the correct engine oil viscosity.
Ignition on, engine off.
With the scan tool, read DTCs.
Is the DTC active at this time?
Ye s>>
Go to 2
No>>
Te s t C o m p l e t e .
2.ENGINE OIL
NOTE: If any engine oil pressure or oil temperature DTCs set along with P1521, repair them before continu-
ing with the P1521 diagnostics.
The following conditions must be checked.
OEM recommended oil viscosity is being used.
Customer is following the oil change schedule.
Check the engine oil for contamination. (i.e., fuel and/or engine coolant)
Internal engine condition that may effect oil pressure.
Were any of the above condition found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Change the engine oil using the correct oil viscosity.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

P3400-MDS RATIONALITY BANK 1
For a complete wiring diagramRefer to Section 8W.
Theory of Operation
When all criteria has been met, power is supplied to each MDS Solenoid when the engine is making a transition
from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that
coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse,
decoupling the valves and camshaft.
When Monitored:
Transition from 8 to 4 cylinder mode.
Set Condition:
O2 sensor readings on Bank 1 side indicate a lean condition while in 4 cylinder mode. One trip fault.
Possible Causes
INSUFFICIENT OIL PRESSURE ACTING ON THE LIFTER LOCKING PINS
OIL PASSAGES RESTRICTED
LIFTER
MDS SOLENOID
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
NOTE: Diagnose any Oil Pressure DTCs before continuing.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.MDS SOLENOID 1
Turn the ignition off.
Remove the Intake Manifold per Service Information.
Turn the ignition on.
With the scan tool actuate the MDS Solenoid 1.
Can you feel and hear the Solenoid Actuating?
Ye s>>
Go To 3
No>>
Remove the Solenoid and check for any debris that may be blocking the oil passages to the Solenoid.
If the passages are clogged, clean the passages and replace the MDS Solenoid1.Ifthepassagesare
not clogged with debris, replace the MDS Solenoid 1.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

For a complete wiring diagramRefer to Section 8W.
Theory of Operation
When all criteria has been met, power is supplied to each MDS Solenoid when the engine is making a transition
from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that
coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse,
decoupling the valves and camshaft.
When Monitored:
Transition from 8 to 4 cylinder mode.
Set Condition:
When the PCM recognizes a problem with the Solenoid Control circuit. One trip fault.
Possible Causes
(K451) MDS SOLENOID NO.1 CONTROL SHORT TO BATTERY VOLTAGE
(K451) MDS SOLENOID NO.1 CONTROL SHORT TO GROUND
(K451) MDS SOLENOID NO.1 CONTROL OPEN
(Z903) GROUND CIRCUIT OPEN
MDS SOLENOID NO.1
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.MDS SOLENOID NO.1
Turn the ignition off.
Gain access to the MDS Solenoid No.1.
Disconnect the MDS Solenoid No.1 harness connector.
Ignition on, engine not running.
Turn off all accessories.
Using a 12-volt test light connected to the (Z903) Ground circuit, probe
the (K451) MDS Solenoid No.1 Control circuit.
With a scan tool, actuate the MDS Solenoid 1.
Does the 12-volt test light flash on and off?
Ye s>>
Replace the MDS Solenoid No.1.
Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3

For a complete wiring diagramRefer to Section 8W.
Theory of Operation
When all criteria has been met, power is supplied to each MDS Solenoid when the engine is making a transition
from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that
coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse,
decoupling the valves and camshaft.
When Monitored:
Transition from 8 to 4 cylinder mode.
Set Condition:
The MDS fails to disengage for cylinder 1. One trip fault.
Possible Causes
(K451) MDS SOLENOID NO.1 CONTROL SHORT TO VOLTAGE
OIL PASSAGES RESTRICTED
LIFTER
MDS SOLENOID NO.1
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.MDS SOLENOID NO.1 CONTROL CIRCUIT
Turn the ignition off.
Disconnect the MDS Solenoid No.1 harness connector.
Ignition on, engine not running.
Turn off all accessories.
Using a 12-volt test light connected to ground, probe the (K451) MDS
Solenoid No.1 Control circuit.
Does the 12-volt test light illuminate?
Ye s>>
Go To 3
No>>
Go To 4