Jeep Grand Cherokee WJ. Manual - part 647

TEST

ACTION

APPLICABILITY

Turn the ignition off.
Disconnect the Fuel Injection Pump harness connector.
Measure the resistance between the following cavities in the Fuel Injection Pump
connector (fuel pump side):
Cavity 1 to cavities 4, 5, 6, 7, 8, 9, and 10.
Cavity 4 to cavities 5, 6, 7, 8, 9, and 10.
Cavity 5 to cavities 6, 7, 8, and 9.
Cavity 7 to cavities 6, 8, 9, and 10.
Cavity 8 to cavities 6 and 10.
NOTE: The resistance should be above 100 ohms for all measurements.
Is the resistance above 100 ohms for each of the measurements?

All

Yes

→

Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.

→

Replace the Fuel Injection Pump in accordance with the Service
Information.
Perform ROAD TEST VERIFICATION - VER-2.

WARNING: 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

Yes

→

Repair as necessary
Perform ROAD TEST VERIFICATION - VER-2.

→

Test Complete.

144

DRIVEABILITY - DIESEL

P1220-FUEL QUANTITY ACTUATOR NEG GOV DEVIATION WARM —

Continued

Symptom List:

P1220-FUEL QUANTITY ACTUATOR POS GOV DEVIATION COLD
P1220-FUEL QUANTITY ACTUATOR POS GOV DEVIATION WARM

Test Note:

All symptoms listed above are diagnosed using the same tests.

The title for the tests will be P1220-FUEL QUANTITY ACTU-
ATOR POS GOV DEVIATION COLD.

When Monitored and Set Condition:

P1220-FUEL QUANTITY ACTUATOR POS GOV DEVIATION COLD

When Monitored:

With the engine running.

Set Condition:

The ECM has attempted to compensate for a lean condition and the engine

coolant temperature is below 60° C (140° F).

P1220-FUEL QUANTITY ACTUATOR POS GOV DEVIATION WARM

When Monitored:

With the engine running.

Set Condition:

The ECM has attempted to compensate for a lean condition and the engine

coolant temperature is above 60° C (140° F).

POSSIBLE CAUSES

INTERMITTENT CONDITION

CHECK THE FUEL INJECTION PUMP TIMING

CHECK FOR A FUEL RESTRICTION

REPLACE THE FUEL INJECTION PUMP

ENGINE CONTROL MODULE

TEST

ACTION

APPLICABILITY

Turn the ignition on.
With the DRB, erase ECM DTCs.
Start the engine and vary the engine speed from idle to 3500 RPM several times.
With the DRB, read ECM DTCs.
Did this DTC reset?

All

Yes

→

Go To

→

Go To

Check the Fuel Injection Pump timing using the Service Information.
Is the Fuel Injection Pump timing correct?

All

Yes

→

Go To

→

Set the Fuel Injection Pump timing in accordance with the
Service Information.
Perform ROAD TEST VERIFICATION - VER-2.

145

DRIVEABILITY - DIESEL

TEST

ACTION

APPLICABILITY

Turn the ignition off.
Inspect the fuel system for restrictions in the delivery lines, filter and/or at the fuel
level sensor module.
Was a restriction found?

All

Yes

→

Repair as necessary.
Perform ROAD TEST VERIFICATION - VER-2.

→

Go To

Turn the ignition off.
Replace the Fuel Injection Pump in accordance with the Service Information.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Start the engine and vary the engine speed from idle to 3500 RPM several times.
With the DRB, read ECM DTCs.
Did this DTC reset?

All

Yes

→

Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.

→

The repair is complete.
Perform ROAD TEST VERIFICATION - VER-2.

All

Yes

→

Repair as necessary
Perform ROAD TEST VERIFICATION - VER-2.

→

Test Complete.

146

DRIVEABILITY - DIESEL

P1220-FUEL QUANTITY ACTUATOR POS GOV DEVIATION COLD —

Continued

Symptom List:

P1225-CONTROL SLEEVE SENSOR SIGNAL HIGH EXCEEDED
P1225-CONTROL SLEEVE SENSOR SIGNAL LOW EXCEEDED

Test Note:

All symptoms listed above are diagnosed using the same tests.

The title for the tests will be P1225-CONTROL SLEEVE SEN-
SOR SIGNAL HIGH EXCEEDED.

When Monitored and Set Condition:

P1225-CONTROL SLEEVE SENSOR SIGNAL HIGH EXCEEDED

When Monitored:

With the ignition on and during after-run mode (at key-off).

Set Condition:

The ECM does not receive a correct signal from the measure coil and/or

the sensor coil. NOTE: This fault will cause the engine to stumble and/or stall.

P1225-CONTROL SLEEVE SENSOR SIGNAL LOW EXCEEDED

When Monitored:

With the ignition on and during after-run mode (at key-off).

Set Condition:

The ECM does not receive a correct signal from the measure coil and/or

the sensor coil.

POSSIBLE CAUSES

INTERMITTENT CONDITION

FUEL INJECTION PUMP - CONTROL SLEEVE POSITION SENSOR OPEN

FUEL INJECTION PUMP - CONTROL SLEEVE POSITION SENSOR SHORTED TO GROUND

CONTROL SLEEVE POSITION SENSOR CIRCUIT SHORTED TO GROUND

CONTROL SLEEVE POSITION SENSOR CIRCUITS SHORTED TOGETHER

CONTROL SLEEVE POSITION SENSOR CIRCUITS OPEN

CONTROL SLEEVE POSITION SENSOR CIRCUITS SHORTED TO VOLTAGE

ENGINE CONTROL MODULE

TEST

ACTION

APPLICABILITY

Turn the ignition on.
With the DRB, erase ECM DTCs.
Turn the ignition off and wait for at least 30 seconds.
Turn the ignition on.
Monitor the DRB for ECM DTCs.
Did this DTC reset?

All

Yes

→

Go To

→

Go To

147

DRIVEABILITY - DIESEL

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