Jeep Grand Cherokee WK. Manual - part 957

P0339-CRANKSHAFT POSITION SENSOR INTERMITTENT (CONTINUED)

For the Engine circuit diagram (Refer to 9 - ENGINE - SCHEMATICS AND DIAGRAMS).

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
While cranking the engine and with the engine running.

•

Set Condition:
When the CKP Sensor failure counter reaches 20. One Trip Fault. Three good trips to turn off the MIL.

Possible Causes

(F855) 5-VOLT SUPPLY CIRCUIT OPEN

(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND

(K24) CKP SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

(K24) CKP SIGNAL CIRCUIT OPEN

(K24) CKP SIGNAL CIRCUIT SHORTED TO GROUND

(K24) CKP SIGNAL CIRCUIT SHORTED TO THE (F855) 5-VOLT SUPPLY CIRCUIT

CRANKSHAFT POSITION SENSOR

TONE WHEEL/PULSE RING

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).

Diagnostic Test

ACTIVE DTC

Ignition on, engine not running.

With a scan tool read DTCs.

Is the DTC active at this time?

Yes

>> Go To 2

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

CHECKING CRANKSHAFT POSITION SENSOR SIGNAL WITH A LAB SCOPE

Turn the ignition off.

With a lab scope probe and the Miller special tool #6801, backprobe the (K24) CKP Signal circuit in the Sensor
harness connector.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands
near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in
personal injury or death.
Ignition on, engine not running.

Observe the lab scope screen.

Start the engine.

Observe the lab scope screen.

Are there any irregular or missing signals?

Yes

>> Go To 3

>> Go To 8

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ENGINE ELECTRICAL DIAGNOSTICS

P0339-CRANKSHAFT POSITION SENSOR INTERMITTENT (CONTINUED)

WIRE HARNESS INSPECTION

Turn the ignition off.

Visually inspect the related wire harness including the ground circuit.
Look for any chafed, pierced, pinched, or partially broken wires.

Visually inspect the related wire harness connectors. Look for broken,
bent, pushed out, or corroded terminals.

Make sure the Crankshaft Position Sensor and the Camshaft Position
Sensor are properly installed and the mounting bolt(s) are torqued to
the proper specification.

Refer to any TSBs that may apply.

Were any of the above conditions present?

Yes

>> Repair as necessary.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

>> Go To 4

(F855) 5-VOLT SUPPLY CIRCUIT OPEN OR SHORTED TO GROUND

Disconnect the CKP Sensor connector.

Ignition on, engine not running.

Measure the voltage on the (F855) 5-volt Supply circuit in the Sensor
harness connector.

Is the voltage between 4.5 and 5.2 volts?

Yes

>> Go To 5

>> Repair the open or short to ground in the (F855) 5-volt

Supply circuit. Use Miller special tool #8815 when check-
ing for an open circuit to prevent PCM harness connector
terminal damage.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

ENGINE ELECTRICAL DIAGNOSTICS

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P0339-CRANKSHAFT POSITION SENSOR INTERMITTENT (CONTINUED)

TONE WHEEL/FLEX PLATE INSPECTION

Turn the ignition off.

Carefully disconnect the Negative Battery (Ground) cable.

Remove the Crankshaft Position Sensor.

Inspect the Tone Wheel/Flex Plate slots for damage, foreign material, or excessive movement.

Were any problems found?

Yes

>> Repair or replace the Tone Wheel/Flex Plate as necessary.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

>> Go To 6

CHECKING CAMSHAFT POSITION SENSOR SIGNAL WITH A LAB SCOPE

Install the CKP Sensor and connect the battery cable.

NOTE: An intermittent condition in the Cam Position Sensor can cause the P0339 to set.
With the a lab scope probe and the Miller special tool #6801, backprobe the (K44) CMP Signal circuit in the Sensor
harness connector.

Wiggle the related wire harness and lightly tap on the Cam Position Sensor.

Observe the lab scope screen.

Start the engine.

Observe the lab scope screen.

Are there any irregular or missing signals?

Yes

>> Replace the Cam Position Sensor.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

>> Go To 7

CRANKSHAFT POSITION SENSOR

If there are no possible causes remaining, view repair.

Repair

Replace the Crankshaft Position Sensor.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

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ENGINE ELECTRICAL DIAGNOSTICS

P0339-CRANKSHAFT POSITION SENSOR INTERMITTENT (CONTINUED)

(K24) CKP SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

Turn the ignition off.

Disconnect the C2 PCM harness connector.

Disconnect the CKP Sensor harness connector.

Ignition on, engine not running.

Measure the voltage on the (K24) CKP Signal circuit in the Sensor
harness connector.

Wiggle the related wire harness while taking this measurement.

Is the voltage above 0 volts?

Yes

>> Repair the short to battery voltage in the (K24) CKP Signal

circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

>> Go To 9

(K24) CKP SIGNAL CIRCUIT OPEN

Turn the ignition off.

CAUTION: Do not probe the PCM harness connectors. Probing
the PCM harness connectors will damage the PCM terminals
resulting in poor terminal to pin connection. Install Miller Special
Tool #8815 to perform diagnosis.
Measure the resistance in the (K24) CKP Signal circuit from the CKP
harness connector to the appropriate terminal of special tool #8815.

Wiggle the wire harness while taking this measurement.

Is the resistance below 1.0 ohm?

Yes

>> Go To 10

>> Repair the excessive resistance in the (K24) CKP Signal

circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

ENGINE ELECTRICAL DIAGNOSTICS

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