Jeep XJ. Manual - part 615

TEST

ACTION

APPLICABILITY

Replace the Fuel Injection Pump in accordance with the Service Information.
With the DRB, erase ECM DTCs.
Perform several drive cycles, turning the ignition off for at least 10 seconds between
each drive cycle.
Monitor the DRB for 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.

WARNING: KEEP CLEAR OF THE ENGINE’S MOVING PARTS.
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.

112

DRIVEABILITY - DIESEL

P1230-TIMING GOVERNING NEGATIVE GOVERNOR DEVIATION —

Continued

Symptom:

P1230-TIMING GOVERNING POSITIVE GOVERNOR DEVIATION

When Monitored and Set Condition:

P1230-TIMING GOVERNING POSITIVE GOVERNOR DEVIATION

When Monitored:

With the engine speed between 1000 and 4800 RPM.

Set Condition:

The ECM detects 3 degrees of excess timing advance for at least 10

seconds.

POSSIBLE CAUSES

ENGINE CONTROL MODULE

REPLACE THE FUEL INJECTION PUMP

INTERMITTENT CONDITION

FUEL SYSTEM RESTRICTIONS

FUEL INJECTION PUMP TIMING INCORRECT

TEST

ACTION

APPLICABILITY

Turn the ignition on.
With the DRB, erase ECM DTCs.
Turn the ignition off, wait 30 seconds, then attempt to start the engine.
With the DRB, read ECM DTCs.
Did this DTC reset?

All

Yes

→

Go To

→

Go To

NOTE: This DTC will set due to low fuel volume to the Fuel Injection Pump.
Check the fuel system for restrictions.
Were any problems found?

All

Yes

→

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

→

Go To

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

All

Yes

→

Go To

→

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

113

DRIVEABILITY - DIESEL

TEST

ACTION

APPLICABILITY

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.

114

DRIVEABILITY - DIESEL

P1230-TIMING GOVERNING POSITIVE GOVERNOR DEVIATION —

Continued

Symptom List:

P1515-ACCEL. PEDAL SENSOR PLAUSIBILITY
P1515-ACCEL. PEDAL SENSOR PWG PLAUS WITH POTENTIOME-
TER
P1515-ACCEL. PEDAL SENSOR SIGNAL HIGH EXCEEDED
P1515-ACCEL. PEDAL SENSOR SUPPLY HIGH EXCEEDED
P1515-ACCEL. PEDAL SENSOR SUPPLY LOW EXCEEDED

Test Note:

All symptoms listed above are diagnosed using the same tests.

The title for the tests will be P1515-ACCEL. PEDAL SENSOR
PLAUSIBILITY.

When Monitored and Set Condition:

P1515-ACCEL. PEDAL SENSOR PLAUSIBILITY

When Monitored:

With the ignition on.

Set Condition:

The accelerator pedal position sensor signal is below 0.2 volt (4%) or above

4.5 volts (90%) and the idle switch is not in the correct state. NOTE: The idle switch is
designed to transition when the accel position is approximately 16% (1.00 volt). This code
sets the ECM to Limp-in Mode, which includes a fixed engine speed of 1100 RPM.

P1515-ACCEL. PEDAL SENSOR PWG PLAUS WITH POTENTIOMETER

When Monitored:

With the ignition on.

Set Condition:

The accelerator pedal position sensor signal is below 0.20 volts, the idle

switch transitions at too high a percentage intermittently or the idle switch is not in the
correct state intermittently. NOTE: The idle switch is designed to transition when the accel
position is approximately 16% (1.00 volt). This code sets the ECM to Limp-in Mode, which
includes a fixed engine speed of 1100 RPM.

P1515-ACCEL. PEDAL SENSOR SIGNAL HIGH EXCEEDED

When Monitored:

With the ignition on.

Set Condition:

The accelerator pedal position sensor signal voltage is above 4.5 volts.

NOTE: This code sets the ECM to Limp-in Mode, which includes a fixed engine speed of
1100 RPM.

P1515-ACCEL. PEDAL SENSOR SUPPLY HIGH EXCEEDED

When Monitored:

With the ignition on.

Set Condition:

The ECM detects voltage on the accelerator pedal position sensor 5-volt

supply circuit above 5.2 volts.

P1515-ACCEL. PEDAL SENSOR SUPPLY LOW EXCEEDED

When Monitored:

With the ignition on.

Set Condition:

The ECM detects voltage the accelerator pedal position sensor 5-volt

supply circuit below 4.75 volts.

115

DRIVEABILITY - DIESEL

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