TEST ACTION APPLICABILITY
2 Turn the ignition off.
Disconnect the ECM harness connectors.
Connect a jumper wire between ground and the Engine Control Relay Control circuit
in ECM C2 harness connector cavity 44.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Fused Engine Control Relay
Output circuits at the ECM C2 harness connector cavities 1, 3 and 5.
Choose the appropriate result.All
Test light is on for all circuits.
Go To 3
Test light is on for 1 or 2 circuits
Repair the Engine Control Relay Output circuit(s) that did not
illuminate brightly for an open.
Perform ROAD TEST VERIFICATION - VER-2.
Light off for all circuits.
Refer to symptom Checking the ECM Power and Grounds.
Perform ROAD TEST VERIFICATION - VER-2.
3 Turn the ignition off.
Disconnect all of the Cylinder Fuel Injector harness connectors.
Disconnect the ECM harness connectors.
Remove the Engine Control Relay from Fuse Block No.1
Connect a jumper wire between cavity 30 and cavity 87 of the Engine Control Relay
connector in Fuse Block No.1.
Turn the ignition on.
Measure the voltage of all of the Fuel Injector Control circuit.
Is the voltage above 1.0 volt for any of the measurements?All
Ye s!Repair the appropriate Fuel Injector Control circuit for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 4
4 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect all of the Fuel Injector harness connectors.
Measure the resistance between ground and all of the Fuel Injector Control circuit.
Is the resistance below 1000 ohms for any of the measurements?All
Ye s!Repair the Fuel Injector Control circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 5
5 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect all of the Cylinder Fuel Injector harness connectors.
Measure the resistance between Fuel Injector No. 1 harness connector cavities 1 and
2.
Repeat the previous step for injectors 2, 3, 4, and 5.
Is the resistance below 1000 ohms for any of the measurements?All
Ye s!Repair the Fuel Injector Control circuit and Common Driver
circuit for a short together.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 6
64
DRIVEABILITY - DIESEL
P0201-CYLINDER 1-INJECTOR CIRCUIT EXCESSIVE CURRENT Ð
Continued
TEST ACTION APPLICABILITY
8 Turn the ignition off.
Disconnect the APP Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the Sensor Ground circuit between the APP Sensor and the
ECM.
Is the resistance below 10.0 ohms?All
Ye s!Go To 9
No!Repair the APP Sensor Ground circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
9 Turn the ignition off.
Disconnect the APP Sensor harness connector.
Using a 12-volt test light connected to 12-volts, check the Sensor Ground circuit of
the appropriate potentiometer.
Does the test light illuminate brightly?All
Ye s!Replace the Accelerator Pedal Position Sensor.
Perform ROAD TEST VERIFICATION - VER-2.
No!Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
10 Turn the ignition off.
Disconnect the APP Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the APP Sensor Signal circuit.
Is the resistance below 10.0 ohms?All
Ye s!Go To 11
No!Repair the APP Sensor Signal circuit for an open
Perform ROAD TEST VERIFICATION - VER-2.
11 Turn the ignition off.
Disconnect the APP Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between ground and the APP Sensor Signal circuit.
Is the resistance below 1000 ohms?All
Ye s!Repair the APP Sensor Signal circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 12
12 Turn the ignition off.
Disconnect the APP Sensor harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between the APP Sensor Signal circuit and the Sensor
Ground circuit at the APP Sensor harness connector.
Is the resistance below 1000 ohms?All
Ye s!Repair the APP Sensor Signal and Sensor Ground circuits for a
short together.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 13
76
DRIVEABILITY - DIESEL
P1222-ACC PEDAL POSITION SENSOR 1 CKT PLAUSIBILITY ÐContinued
TEST ACTION APPLICABILITY
2 Turn the ignition off.
Disconnect the ECM harness connectors.
Connect a jumper wire between ground and the Engine Control Relay Control circuit
in ECM C2 harness connector cavity 44.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Fused Engine Control Relay
Output circuits at the ECM C2 harness connector cavities 1, 3 and 5.
Choose the appropriate result.All
Test light is on for all circuits.
Go To 3
Test light is on for 1 or 2 circuits
Repair the Engine Control Relay Output circuit(s) that did not
illuminate brightly for an open.
Perform ROAD TEST VERIFICATION - VER-2.
Light off for all circuits.
Refer to symptom Checking the ECM Power and Grounds.
Perform ROAD TEST VERIFICATION - VER-2.
3 Turn the ignition off.
Disconnect the Water In Fuel Sensor harness connector.
Turn the ignition on.
Measure the voltage of the Water In Fuel 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 6
Voltage is below 4.7 volts.
Go To 8
4 Turn the ignition off.
Disconnect the In Fuel Level Sensor harness connector.
Disconnect the ECM harness connectors.
Remove the Engine Control Relay.
Connect a jumper wire between cavity 30 and cavity 87 of the Engine Control Relay
connector.
Turn the ignition on.
Measure the voltage of the Water In Fuel Sensor Signal circuit.
Is the voltage below 1.0 volt?All
Ye s!Go To 5
No!Repair the Water In Fuel Sensor Signal circuit for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
107
DRIVEABILITY - DIESEL
P2009-WATER IN FUEL SENSOR - WATER IN FUEL ÐContinued
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
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:
P2100-FUEL PUMP RELAY CIRCUIT OPEN CIRCUIT
P2100-FUEL PUMP RELAY CIRCUIT SHORTED TO GROUND
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2100-FUEL PUMP RELAY
CIRCUIT OPEN CIRCUIT.
POSSIBLE CAUSES
INTERMITTENT CONDITION
ENGINE CONTROL RELAY OUTPUT CIRCUIT OPEN
FUEL LIFT PUMP RELAY
FUEL LIFT PUMP RELAY CONTROL CIRCUIT SHORTED TO GROUND
FUEL LIFT PUMP RELAY CONTROL CIRCUIT OPEN
ENGINE CONTROL MODULE
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 DRBIIIt, erase the ECM DTCs.
Crank and attempt to start the engine several times.
With the DRBIIIt, read the active ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 6
2 Turn the ignition off.
Remove the Fuel Lift Pump Relay.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Engine Control Relay
Output circuit.
Did the test light illuminate brightly?All
Ye s!Go To 3
No!Refer to Checking the ECM Power and Grounds for the related
symptom(s).
Perform ROAD TEST VERIFICATION - VER-2.
157
DRIVEABILITY - DIESEL
TEST ACTION APPLICABILITY
2NOTE: If DTC P1611, P2306 or P2332 is present with this DTC, diagnose
DTCs P1611, P2306 or P2332 before diagnosing this DTC.
NOTE: Check the ECM for other ECM DTC's related to circuits that are
open, shorted to ground or low voltage problems.
Does the DRB also display these type of DTC's?All
Ye s!Go To 3
No!Go To 4
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Turn the ignition on.
Connect a jumper wire between ground and the Engine Control Relay Signal circuit
in ECM C2 harness connector cavity 44.
Using a 12-volt test light connected to ground, check the Fused Engine Control Relay
Output circuits at the ECM C2 harness connector cavities 1, 3 and 5.
Does the test light illuminate brightly for each circuit?All
Ye s!Go To 4
No!Refer to symptom list and perform Checking the ECM Power and
Grounds.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Install a substitute relay in place of the Starter Relay.
Turn the ignition on.
With the DRBIIIt, erase DTCs.
Attempt to start the engine several times, pausing for at least 10 seconds between
each cycle.
Turn the ignition on.
With the DRB, read ECM DTCs.
Did this DTC set again?All
Ye s!Go To 5
No!Replace the Starter Relay.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Remove the Starter Relay.
Disconnect the ECM harness connectors.
Measure the resistance of the Starter Relay Control circuit.
Is the resistance below 10.0 ohms?All
Ye s!Go To 6
No!Repair the Starter Relay Control circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
6 Turn the ignition off.
Remove the Starter Relay.
Disconnect the ECM harness connectors.
Measure the resistance between ground and the Starter Relay Control circuit.
Is the resistance above 1000 ohms?All
Ye s!Go To 7
No!Repair the Starter Relay Control circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
162
DRIVEABILITY - DIESEL
P2104-STARTER RELAY CIRCUIT SHORT CIRCUIT ÐContinued
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.
Test drive the vehicle.
Monitor the DRB for ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 8
2NOTE: Check the ECM for other ECM DTC's related to circuits that are
open, shorted to ground or low voltage problems.
Does the DRB also display these type of DTC's?All
Ye s!Go To 3
No!Go To 4
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Connect a jumper wire between ground and the Engine Control Relay Signal circuit
in ECM C2 harness connector cavity 44.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Fused Engine Control Relay
Output circuits at the ECM C1 harness connector cavities 1, 3 and 5.
Does the test light illuminate brightly for each circuit?All
Ye s!Go To 4
No!Refer to symptom list and perform Checking the ECM Power and
Grounds.
Perform ROAD TEST VERIFICATION - VER-2.
4 Turn the ignition off.
Disconnect the Boost Pressure Servo Motor harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the 12 Volt Supply circuit in the
Boost Pressure Servo Motor harness connector.
Does the test light illuminate brightly?All
Ye s!Go To 5
No!Repair the 12 Volt Supply circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
168
DRIVEABILITY - DIESEL
P2111-BOOST PRESSURE SERVO MOTOR CIRCUIT SHORT TO
GROUND Ð
Continued