
TEST ACTION APPLICABILITY
5NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB IIItat the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
NOTE: Refer to the Service Information and perform the Air Bleed Proce-
dure before continuing diagnosis.
Turn the ignition on.
With the DRBIIIt, erase the ECM DTCs.
Start and idle the engine while monitoring for ECM DTC's.
If the DTC does not reset at idle condition, test drive the vehicle under various load
and speed conditions to attempt to duplicate the fault.
NOTE: Driving the vehicle up and down steep hills or rapid cornering with
a low fuel level can cause this DTC to set. Verify with customer if Low Fuel
Light was illuminated when fault occurred.
With the DRBIIIt, read the ECM DTCs.
Does the DRBIIItdisplay this DTC?All
Ye s!Go To 6
No!Go To 16
6 Start the engine.
With the DRBIIItin Sensors, compare the Fuel Pressure Setpoint with the Actual
Fuel Pressure readings.
NOTE: If there is air in the fuel system, the Actual Fuel Pressure will
oscillate above and below the Fuel Pressure Setpoint.
Does Actual Fuel Pressure oscillate above and below the Fuel Pressure Setpoint?All
Ye s!Refer to the Service Information to purge air from the fuel system.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 7
7 Start the engine.
With the DRBIIItin Sensors, compare the Fuel Pressure Setpoint with the Actual
Fuel Pressure readings.
NOTE: A sticking Fuel Pressure Solenoid is indicated by Actual Fuel
Pressure gradually dropping below the Fuel Pressure Setpoint then sud-
denly increasing (spiking) above the Fuel Pressure Setpoint.
Does Actual Fuel Pressure gradually decrease then suddenly increase (spike) above
the Fuel PressureAll
Ye s!Replace the Fuel Pressure Solenoid in accordance with the
Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 8
120
DRIVEABILITY - DIESEL
P2015-FUEL RAIL PRESSURE MALFUNCTION MAXIMUM FUEL FLOW
EXCEEDED Ð
Continued

TEST ACTION APPLICABILITY
13 With the DRBIIIt, select System Tests, then perform the Rail Press Control Valve
Test.
Did this test pass?All
Ye s!Go To 14
No!Replace the Fuel Pressure Solenoid in accordance with the
Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
14 With the DRBIIIt, select System Tests, then perform the Rail Press Control Valve
Variation Test.
Did this test pass?All
Ye s!Go To 15
No!Replace the Fuel Pressure Solenoid in accordance with the
Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
15 With the DRBIIIt, select System Test, then High Pressure Pump.
NOTE: During this test engine speed is set at 1,400 rpm and initial fuel
pressure at approximately 6,800 psi. During the test fuel pressure is
instantly set to above 20,000 psi. to test the performance of the Fuel
Injection Pump.
NOTE: After the test is completed, the DRB display fuel pressure in 30
counter steps. If the fuel pressure increases from approximately 6,800 psi to
above 20,000 psi in one counter step, the injection pump passes the test.
Did the fuel pressure increase to above 20,000 psi within one counter step on the
DRB?All
Ye s!Replace the Fuel Quantity Solenoid in accordance with the
Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Replace Fuel Injection Pump in accordance with the Service
Information.
Perform ROAD TEST VERIFICATION - VER-2.
16WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running and at normal operating temperature, monitor the DRB IIIt
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DTC When Monitored and Set Conditions. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s!Repair as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
No!Test Complete.
122
DRIVEABILITY - DIESEL
P2015-FUEL RAIL PRESSURE MALFUNCTION MAXIMUM FUEL FLOW
EXCEEDED Ð
Continued

Symptom:
P2025-INTAKE PRESSURE SENSOR PLAUSIBILITY
When Monitored and Set Condition:
P2025-INTAKE PRESSURE SENSOR PLAUSIBILITY
When Monitored: With the ignition on.
Set Condition: The Intake Pressure Sensor signal does not agree with the Atmospheric
Pressure Sensor signal in the ECM.
POSSIBLE CAUSES
AIR FILTER
AIR RESTRICTION
INTERMITTENT CONDITION
HIGH RESISTANCE IN THE INTAKE PRESSURE SENSOR SIGNAL CIRCUIT
HIGH RESISTANCE IN THE INTAKE PRESSURE SENSOR GROUND CIRCUIT
HIGH RESISTANCE IN THE INTAKE PRESSURE SENSOR 5-VOLT SUPPLY CIRCUIT
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1NOTE: If DTC P1611, P2306 or P2332 is present with this DTC, diagnose
DTCs P1611, P2306 or P2332 before diagnosing this DTC.
NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Turn the ignition off, wait 30 seconds.
Test drive the vehicle.
With the DRB, read ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 7
2 Turn the ignition off.
Remove and inspect the Air Filter for soiling or excessive dirt and debris which may
cause air flow restriction.
Were any of these problems found?All
Ye s!Replace the Air Filter element.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 3
125
DRIVEABILITY - DIESEL

Symptom List:
P2025-INTAKE PRESSURE SENSOR SIGNAL VOLTAGE TOO HIGH
P2030-INTAKE PRESSURE SENSOR CIRCUIT FAULT
P2030-INTAKE PRESSURE SENSOR OPEN CIRCUIT
P2030-INTAKE PRESSURE SENSOR SIGNAL VOLTAGE TOO HIGH
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2025-INTAKE PRESSURE
SENSOR SIGNAL VOLTAGE TOO HIGH.
POSSIBLE CAUSES
INTERMITTENT CONDITION
INTAKE PRESSURE SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE
INTAKE PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
INTAKE PRESSURE SENSOR GROUND CIRCUIT OPEN
INTAKE PRESSURE SENSOR
ENGINE CONTROL MODULE (INTERNAL)
ENGINE CONTROL MODULE (SENSOR SIGNAL SHORTED TO VOLTAGE)
TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
NOTE: Ensure all turbocharger inlet and outlet tubes are connected prop-
erly, without damage and restriction before continuing with this test. Also
ensure the Boost Pressure Servo Motor and Servo Motor rod are attached
and functioning properly.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Cycle the ignition key on and off several times, leaving the key on for at least 10
seconds at a time.
With the DRB, read ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 7
128
DRIVEABILITY - DIESEL

Symptom List:
P2025-INTAKE PRESSURE SENSOR SIGNAL VOLTAGE TOO LOW
P2030-INTAKE PRESSURE SENSOR SIGNAL VOLTAGE TOO LOW
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2025-INTAKE PRESSURE
SENSOR SIGNAL VOLTAGE TOO LOW.
POSSIBLE CAUSES
INTERMITTENT CONDITION
INTAKE PRESSURE SENSOR 5 VOLT SUPPLY
INTAKE PRESSURE SENSOR
INTAKE PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
INTAKE PRESSURE SENSOR SIGNAL AND GROUND CIRCUITS SHORTED TOGETHER
ENGINE CONTROL MODULE
INTAKE PRESSURE SENSOR SIGNAL CIRCUIT OPEN
TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
NOTE: Ensure all turbocharger inlet and outlet tubes are connected prop-
erly, without damage and restriction before continuing with this test. Also
ensure the Boost Pressure Servo Motor and Servo Motor rod are attached
and functioning properly.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Cycle the ignition key on and off several times, leaving the key on for at least 10
seconds at a time.
With the DRB, read ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 7
2 Turn the ignition off.
Disconnect the Intake Pressure Sensor harness connector.
Turn the ignition on.
Measure the voltage between ground and the Intake Pressure Sensor 5 Volt Supply
circuit.
Is the voltage above 4.8 volts?All
Ye s!Go To 3
No!Repair the Intake Pressure Sensor 5 Volt Supply circuit for an
open.
Perform ROAD TEST VERIFICATION - VER-2.
131
DRIVEABILITY - DIESEL

TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Turn the ignition off for 10 seconds.
Test drive the vehicle.
Monitor the DRB for ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 9
2 Turn the ignition off.
Using the Service Information wiring diagrams, inspect the wiring and connectors
between the ECM and the O2 sensor for damage, corrosion, poor terminal contact or
other problems.
Were any problems found?All
Ye s!Clean, repair or replace as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 3
3 Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Power Supply circuit at the
O2 harness connector cavity 4.
Does the test light illuminate brightly?All
Ye s!Go To 4
No!Repair the Power Supply circuit for an open or short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Disconnect the ECM harness connectors.
Perform the following resistance measurements from the O2 harness connector to the
ECM harness connector.
O2 Sensor Cavity 1 to ECM Cavity C1-15.
O2 Sensor Cavity 2 to ECM Cavity C1-40.
O2 Sensor Cavity 3 to ECM Cavity C1-72.
O2 Sensor Cavity 5 to ECM Cavity C1-62.
O2 Sensor Cavity 6 to ECM Cavity C1-39.
Is the resistance below 10.0 ohms for each measurement?All
Ye s!Go To 5
No!Repair the circuit(s) that measured above 10.0 ohms for an open.
Perform ROAD TEST VERIFICATION - VER-2.
135
DRIVEABILITY - DIESEL
P2026-O2 SENSOR CIRCUIT FAULT ÐContinued

Symptom List:
P2034-O2 SENSOR CIRCUIT CALIBRATION VALUE TOO HIGH
P2034-O2 SENSOR CIRCUIT CALIBRATION VALUE TOO LOW
P2036-O2 SENSOR CIRCUIT CALIBRATION VALUE TOO HIGH
P2036-O2 SENSOR CIRCUIT CALIBRATION VALUE TOO LOW
P2038-O2 SENSOR CIRCUIT CALIBRATION VALUE TOO HIGH
P2038-O2 SENSOR CIRCUIT CALIBRATION VALUE TOO LOW
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2034-O2 SENSOR CIRCUIT
CALIBRATION VALUE TOO HIGH.
POSSIBLE CAUSES
CHECKING CIRCUIT INTEGRITY
O2 SENSOR
INTERMITTENT CONDITION
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Using the Service Information wiring diagrams, inspect the wiring and connectors
between the ECM and the O2 sensor for damage, corrosion, poor terminal contact or
other problems.
Were any problems found?All
Ye s!Clean, repair or replace as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 2
2NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Turn the ignition off for 10 seconds.
Test drive the vehicle.
Monitor the DRB for ECM DTCs.
Did this DTC set again?All
Ye s!Replace the Oxygen Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 3
138
DRIVEABILITY - DIESEL

TEST ACTION APPLICABILITY
1NOTE: If DTC P1611, P2306 or P2332 is present with this DTC, diagnose
DTCs P1611, P2306 or P2332 before diagnosing this DTC.
NOTE: The Timing Belt/Chain must be correctly installed and operational
before diagnosis can be made. Refer to the Service Information to ensure
the timing belt is properly installed.
NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRBIIIt, erase the ECM DTCs.
Attempt to start the engine cranking the engine for at least 7 seconds.
With the DRBIIIt, read the ECM DTCs.
Does the DRBIIItdisplay this DTC?All
Ye s!Go To 4
No!Go To 2
2 Turn the ignition on.
With the DRBIIIt, erase the ECM DTCs.
Test drive the vehicle.
With the DRBIIIt, read the ECM DTCs.
Does the DRBIIItdisplay this DTC?All
Ye s!Go To 3
No!Go To 16
3 Turn the ignition off.
Disconnect the Camshaft Position Sensor harness connector.
Turn the ignition on.
Measure the voltage of the CMP Sensor Signal circuit.
Select the appropriate voltage reading.All
Voltage is above 5.4 volts.
Go To 4
Voltage is between 4.7 and 5.4 volts.
Go To 5
Voltage is below 4.7 volts.
Go To 13
141
DRIVEABILITY - DIESEL
P2043-CAMSHAFT POSITION SENSOR CIRCUIT OPEN CIRCUIT Ð
Continued