Page 1265 of 4284

Symptom List:
P0201-CYLINDER 1-INJECTOR CIRCUIT CURRENT DECREASE
P0201-CYLINDER 1-INJECTOR CIRCUIT LOAD DROP
P0201-CYLINDER 1-INJECTOR CIRCUIT OVERCURRENT HIGH
SIDE
P0201-CYLINDER 1-INJECTOR CIRCUIT OVERCURRENT LOW
SIDE
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0201-CYLINDER 1-INJECTOR
CIRCUIT CURRENT DECREASE.
When Monitored and Set Condition:
P0201-CYLINDER 1-INJECTOR CIRCUIT CURRENT DECREASE
When Monitored: With the engine running.
Set Condition: The ECM detects an incorrect rate of current decrease after injection
occurs.
P0201-CYLINDER 1-INJECTOR CIRCUIT LOAD DROP
When Monitored: With the engine running.
Set Condition: The ECM detects insufficient current through the injector driver.
P0201-CYLINDER 1-INJECTOR CIRCUIT OVERCURRENT HIGH SIDE
When Monitored: With the engine running.
Set Condition: The ECM detects excessive current on the common driver circuit.
P0201-CYLINDER 1-INJECTOR CIRCUIT OVERCURRENT LOW SIDE
When Monitored: With the engine running.
Set Condition: The ECM detects excessive current on the injector driver circuit.
POSSIBLE CAUSES
COMMON DRIVER CIRCUIT OPEN
COMMON DRIVER CIRCUIT SHORTED TO GROUND
ENGINE CONTROL MODULE
FUEL INJECTOR
FUEL INJECTOR #1 DRIVER CIRCUIT OPEN
FUEL INJECTOR #1 DRIVER CIRCUIT SHORTED TO GROUND
INTERMITTENT CONDITION
46
DRIVEABILITY - DIESEL
Page 1266 of 4284

POSSIBLE CAUSES
COMMON DRIVER CIRCUIT SHORTED TO VOLTAGE
FUEL INJECTOR #1 DRIVER CIRCUIT SHORTED TO VOLTAGE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, erase the ECM DTCs.
Test drive the vehicle.
With the DRBIIIt, read the ECM DTCs.
Does the DRB III display DTC P0201?All
Ye s®Go To 2
No®Go To 9
2 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Cylinder #1 Injector harness connector.
Measure the resistance of the Fuel Injector #1 Driver circuit.
Is the resistance below 10.0 ohms?All
Ye s®Go To 3
No®Repair the Fuel Injector #1 Driver circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Cylinder #1 Injector harness connector.
Measure the resistance between ground and the Fuel Injector #1 Driver circuit.
Is the resistance below 1000.0 ohms?All
Ye s®Repair the Fuel Injector #1 Driver circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 4
4 Turn the ignition off.
Disconnect the Cylinder #1 Fuel Injector harness connector.
Disconnect the ECM harness connectors.
Remove the ECM/PCM Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ECM/PCM Relay
connector.
Turn the ignition on.
Measure the voltage of the Fuel Injector #1 Driver circuit.
Is the voltage above 1.0 volt?All
Ye s®Repair the Fuel Injector #1 Driver circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 5
47
DRIVEABILITY - DIESEL
P0201-CYLINDER 1-INJECTOR CIRCUIT CURRENT DECREASE Ð
Continued
Page 1267 of 4284

TEST ACTION APPLICABILITY
5 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Cylinder #1 Injector harness connector.
Measure the resistance of the Common Driver circuit.
Is the resistance below 10.0 ohms?All
Ye s®Go To 6
No®Repair the Common Driver circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
6 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Cylinder #1 Injector harness connector.
Measure the resistance between ground and the Common Driver circuit.
Is the resistance below 1000.0 ohms?All
Ye s®Repair the Common Driver circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 7
7 Turn the ignition off.
Disconnect the Cylinder #1 Fuel Injector harness connector.
Disconnect the ECM harness connectors.
Remove the ECM/PCM Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ECM/PCM Relay
connector.
Turn the ignition on.
Measure the voltage of the Common Driver circuit.
Is the voltage above 1.0 volt?All
Ye s®Repair the Common Driver circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 8
8 Turn the ignition off.
Replace the Cylinder #1 Fuel Injector in accordance with the Service Information.
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®Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No®Test Complete.
48
DRIVEABILITY - DIESEL
P0201-CYLINDER 1-INJECTOR CIRCUIT CURRENT DECREASE Ð
Continued
Page 1268 of 4284

TEST ACTION APPLICABILITY
9WARNING: 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 at normal operating temperature, monitor the DRB
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.
49
DRIVEABILITY - DIESEL
P0201-CYLINDER 1-INJECTOR CIRCUIT CURRENT DECREASE Ð
Continued
Page 1269 of 4284

Symptom List:
P0202-CYLINDER 2-INJECTOR CIRCUIT CURRENT DECREASE
P0202-CYLINDER 2-INJECTOR CIRCUIT LOAD DROP
P0202-CYLINDER 2-INJECTOR CIRCUIT OVERCURRENT HIGH
SIDE
P0202-CYLINDER 2-INJECTOR CIRCUIT OVERCURRENT LOW
SIDE
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0202-CYLINDER 2-INJECTOR
CIRCUIT CURRENT DECREASE.
When Monitored and Set Condition:
P0202-CYLINDER 2-INJECTOR CIRCUIT CURRENT DECREASE
When Monitored: With the engine running.
Set Condition: The ECM detects an incorrect rate of current decrease after injection
occurs.
P0202-CYLINDER 2-INJECTOR CIRCUIT LOAD DROP
When Monitored: With the engine running.
Set Condition: The ECM detects insufficient current through the injector driver.
P0202-CYLINDER 2-INJECTOR CIRCUIT OVERCURRENT HIGH SIDE
When Monitored: With the engine running.
Set Condition: The ECM detects excessive current on the common driver circuit.
P0202-CYLINDER 2-INJECTOR CIRCUIT OVERCURRENT LOW SIDE
When Monitored: With the engine running.
Set Condition: The ECM detects excessive current on the injector driver circuit.
POSSIBLE CAUSES
COMMON DRIVER CIRCUIT OPEN
COMMON DRIVER CIRCUIT SHORTED TO GROUND
ENGINE CONTROL MODULE
FUEL INJECTOR
FUEL INJECTOR #2 DRIVER CIRCUIT OPEN
FUEL INJECTOR #2 DRIVER CIRCUIT SHORTED TO GROUND
INTERMITTENT CONDITION
50
DRIVEABILITY - DIESEL
Page 1270 of 4284

POSSIBLE CAUSES
COMMON DRIVER CIRCUIT SHORTED TO VOLTAGE
FUEL INJECTOR #2 DRIVER CIRCUIT SHORTED TO VOLTAGE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, erase the ECM DTCs.
Test drive the vehicle.
With the DRBIIIt, read the ECM DTCs.
Does the DRB III display DTC P0202?All
Ye s®Go To 2
No®Go To 9
2 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Cylinder #2 Injector harness connector.
Measure the resistance of the Fuel Injector #2 Driver circuit.
Is the resistance below 10.0 ohms?All
Ye s®Go To 3
No®Repair the Fuel Injector #2 Driver circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Cylinder #2 Injector harness connector.
Measure the resistance between ground and the Fuel Injector #2 Driver circuit.
Is the resistance below 1000.0 ohms?All
Ye s®Repair the Fuel Injector #2 Driver circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 4
4 Turn the ignition off.
Disconnect the Cylinder #2 Fuel Injector harness connector.
Disconnect the ECM harness connectors.
Remove the ECM/PCM Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ECM/PCM Relay
connector.
Turn the ignition on.
Measure the voltage of the Fuel Injector #2 Driver circuit.
Is the voltage above 1.0 volt?All
Ye s®Repair the Fuel Injector #2 Driver circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 5
51
DRIVEABILITY - DIESEL
P0202-CYLINDER 2-INJECTOR CIRCUIT CURRENT DECREASE Ð
Continued
Page 1271 of 4284

TEST ACTION APPLICABILITY
5 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Cylinder #2 Injector harness connector.
Measure the resistance of the Common Driver circuit.
Is the resistance below 10.0 ohms?All
Ye s®Go To 6
No®Repair the Common Driver circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
6 Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Cylinder #2 Injector harness connector.
Measure the resistance between ground and the Common Driver circuit.
Is the resistance below 1000.0 ohms?All
Ye s®Repair the Common Driver circuit for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 7
7 Turn the ignition off.
Disconnect the Cylinder #2 Fuel Injector harness connector.
Disconnect the ECM harness connectors.
Remove the ECM/PCM Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ECM/PCM Relay
connector.
Turn the ignition on.
Measure the voltage of the Common Driver circuit.
Is the voltage above 1.0 volt?All
Ye s®Repair the Common Driver circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No®Go To 8
8 Turn the ignition off.
Replace the Cylinder #2 Fuel Injector in accordance with the Service Information.
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®Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No®Test Complete.
52
DRIVEABILITY - DIESEL
P0202-CYLINDER 2-INJECTOR CIRCUIT CURRENT DECREASE Ð
Continued
Page 1272 of 4284

TEST ACTION APPLICABILITY
9WARNING: 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 at normal operating temperature, monitor the DRB
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.
53
DRIVEABILITY - DIESEL
P0202-CYLINDER 2-INJECTOR CIRCUIT CURRENT DECREASE Ð
Continued