Page 356 of 5267

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)
Page 391 of 5267

P3497-MDS RATIONALITY BANK 2
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 2 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 4
Turn the ignition off.
Remove the Intake Manifold per Service Information.
Turn the ignition on.
With the scan tool actuate the MDS Solenoid 4.
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 Solenoid4.Ifthepassagesare
not clogged with debris, replace the MDS Solenoid 4.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 407 of 5267

When Monitored:
Ignition on.
Set Condition:
The PCM doesn’t receive the ambient temperature signal over the CAN C bus from the TIPM. The circuit is
continuously monitored. One Trip fault.
Possible Causes
CAN C BUS CIRCUIT OPEN OR SHORTED
TOTALLY INTEGRATED POWER MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The ambient temperature sensor signal is a direct input to the TIPM. The TIPM sends the PCM the ambient tem-
perature signal over the CAN C bus.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With the scan tool read Powertrain 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.U0141-LOST COMMUNICATION WITH FRONT CONTROL MODULE (TIPM) ALSO ACTIVE
With the scan tool read DTCs.
Is the U0141-NO BUS MESSAGE RECEIVED FROM THE TIPM also set?
Ye s>>
Follow the diagnostics for U0141-LOST COMMUNICATION WITH FRONT CONTROL MODULE (TIPM)
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 420 of 5267

When Monitored:
Ignition on.
Set Condition:
The PCM gets an implausible signal over the CAN C circuit from the ABS Module. The circuit is continuously
monitored. One Trip fault.
Possible Causes
VEHICLE SPEED SENSOR FAULT ACTIVE IN ANTI-LOCK BRAKE MODULE
CAN C BUS CIRCUIT SHORTED
CAN C BUS CIRCUIT OPEN
ABS MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The ABS Module sends an implausible distance signal over the CAN C Bus circuit to the PCM.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the U1417-IMPLAUSIBLE LEFT WHEEL DISTANCE SIGNAL RECEIVED 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.ABS MODULE IS ACTIVE ON THE CAN C BUS
With the scan tool, select ECU View.
Verify that the ABS Module active on the bus.
Is the ABS Module active on the bus?
Ye s>>
Go To 3
No>>
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for No
Response diagnostic procedures.
Perform BODY VERIFICATION TEST – VER 1.
3.DTCS STORED OR ACTIVE IN THE ABS MODULE
Check for DTCs in the ABS Module.
Are any DTCs active or stored in the ABS Module?
Ye s>>
Refer to section 5 - BRAKES - ABS ELECTRICAL DIAGNOSTICS and perform the diagnostics for the
DTCs in the ABS Module.
Perform ABS VERIFICATION TEST – VER 1
No>>
Go to 4
Page 423 of 5267

When Monitored:
Ignition on.
Set Condition:
The PCM gets an implausible signal over the CAN C circuit from the ABS Module. The circuit is continuously
monitored. One Trip fault.
Possible Causes
VEHICLE SPEED SENSOR FAULT ACTIVE IN ANTI-LOCK BRAKE MODULE
CAN C BUS CIRCUIT SHORTED
CAN C BUS CIRCUIT OPEN
ABS MODULE
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The ABS Module sends an implausible distance signal over the CAN C Bus circuit to the PCM.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the U1418-IMPLAUSIBLE RIGHT WHEEL DISTANCE SIGNAL RECEIVED 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.ABS MODULE IS ACTIVE ON THE CAN C BUS
With the scan tool, select ECU View.
Verify that the ABS Module active on the bus.
Is the ABS Module active on the bus?
Ye s>>
Go To 3
No>>
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for No
Response diagnostic procedures.
Perform BODY VERIFICATION TEST – VER 1.
3.DTCS STORED OR ACTIVE IN THE ABS MODULE
Check for DTCs in the ABS Module.
Are any DTCs active or stored in the ABS Module?
Ye s>>
Refer to section 5 - BRAKES - ABS ELECTRICAL DIAGNOSTICS and perform the diagnostics for the
DTCs in the ABS Module.
Perform ABS VERIFICATION TEST – VER 1
No>>
Go to 4
Page 438 of 5267

Possible Causes
MECHANICAL CONDITION
BATTERY CIRCUIT RESISTANCE TOO HIGH
FUSED IGNITION SWITCH OUTPUT CIRCUITS
FUSED B+ CIRCUIT OPEN
(T752) STARTER RELAY CONTROL CIRCUIT OPEN
(T750) STARTER RELAY OUTPUT CIRCUIT OPEN
TRANSMISSION RANGE SENSOR
STARTER RELAY
STARTER
Diagnostic Test
1.MECHANICAL CONDITION
NOTE: Verify the battery is fully charged and capable of passing a load testbefore continuing.
WARNING: Make sure the battery is disconnected, then wait two minutes before proceeding. Failure to do
so may result in personal injury or possible death.
Turn the engine over by hand to make sure the engine is not seized.
Is the engine able to turn over?
Ye s>>
Go To 2
No>>
Repair the mechanical condition preventing the starter motor from cranking.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.TRANSMISSION RANGE SENSOR
Turn the ignition off.
Disconnect the TRS harness connectors.
Move the Gear selector through all gear positions, from Park to 1st and
back.
While moving the gear selector through each gear, measure the resis-
tance between ground and the TRS (T41) Sense (P/N Position Switch
Sense) circuit at the TRS connector.
NOTE: The circuit is grounded in Park and Neutral and open in the
other positions.
Did the resistance change from above 100 kohms (open) to
below 10.0 ohms (grounded) ?
Ye s>>
Go To 3
No>>
Replace the Transmission Range Sensor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
Page 443 of 5267

Possible Causes
(A919) PCM FUSED B+ CIRCUIT
PCM NO RESPONSE
(F202) (F1) (T751) PCM FUSED IGNITION SWITCH OUTPUT CIRCUITS
(Z130) (Z131) PCM GROUND CIRCUITS
CRANKSHAFT POSITION SENSOR
(F855) 5-VOLT SENSOR OPEN/SHORTED
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
PCM
Diagnostic Test
1.(A919) PCM FUSED B+ CIRCUIT
NOTE: The scan tool and cable must be operating properly for the
resultsofthistesttobevalid.
NOTE: Make sure the ignition switch was on while trying to com-
municate with the PCM.
Turn the ignition off.
Disconnect the PCM harness connectors.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
Using a 12-volt test light connected to ground probe the appropriate ter-
minal of special tool #8815.
Does the test light illuminate brightly?
Ye s>>
Go To 2
No>>
Repair the open or short to ground in the (A919) Fused B+
circuit. Inspect and replace fuses as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.(F202), (F1), (T751) PCM FUSED IGNITION SWITCH CIRCUITS
Using a 12-volt test light connected to ground, probe the PCM Fused
Ignition Switch Output circuits in the appropriate terminals of special tool
#8815.
Does the test light illuminate brightly?
Ye s>>
Go To 3
No>>
Repair the (F202) (F1) (T751) Ignition Switch Output cir-
cuits. Inspect and replace fuses as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
Page 444 of 5267
3.(Z130) AND (Z131) PCM GROUND CIRCUITS
Using a 12-volt test light connected to battery voltage, probe the (Z130)
(Z131) PCM ground circuits in the appropriate terminals of special tool
#8815.
Does the test light illuminate brightly?
Ye s>>
Go To 4
No>>
Repair the PCM ground circuits.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
4.(F855) 5-VOLT SUPPLY CIRCUIT
Turn the ignition off.
Connect the PCM harness connectors.
Disconnect the Crankshaft Position Sensor harness connector.
Ignition on, engine not running.
Measure the voltage on the (F855) 5-volt Supply circuit.
Is the voltage between 4.5 and 5.2 volts?
Ye s>>
Go To 5
No>>
Go To 6