Circuit Description
The DTC P0339 Crankshaft Position (CKP) Sensor Circuit Intermittent diagnostic the verifies that the signal from the CKP sensor is continuous. The CKP sensor is a magnetic generator type sensor, producing an alternating current signal. The CKP sensor signal increases in both frequency and amplitude as the engine RPM increases. The CKP sensor sends this reference signal to the powertrain control module (PCM) to indicate the crankshaft RPM and position. This reference signal is used by the PCM to calculate fuel injection pulse, establish top dead center (TDC) for ignition timing and where to start ignition coil and injection sequencing. There will be no spark or fuel delivery if there is no CKP sensor signal.
Conditions for Running the DTC
| • | The engine speed is more than 600 RPM. |
| • | DTC P0339 runs continuously once the above condition has been met. |
Conditions for Setting the DTC
The crankshaft position sensor signal to the PCM is not continuous.
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) during the second key cycle in which the DTC sets. |
| • | The PCM stores the conditions which were present when the DTC set as Freeze Frame data. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the MIL on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present. |
| • | A DTC will clear after 40 consecutive warm-up cycles have occurred without a fault. |
| • | A DTC can be cleared by using the scan tool Clear DTC Information function. |
Diagnostic Aids
| • | Check for any of the following conditions: |
| - | Check the crankshaft position (CKP) sensor output signal with a scan tool. The scan tool will display engine speed while cranking when the PCM detects the CKP sensor signal. Observe the Engine Speed parameter while cranking the engine. The scan tool should indicate a steady 200-300 RPM while cranking. |
| - | The CKP sensor performance may be affected by temperature. Check the sensors operation and internal resistance at various temperatures. The CKP sensor resistance when cold should be between 1,630 ohms and 2,740 ohms at -10 to +50°C (+14 to +122°F). The CKP sensor resistance when hot should be between 2,065 ohms and 3,225 ohms at 50-100°C (122-212°F). |
| - | An intermittent DTC P0339 can be caused by a defective signal rotor. Remove the CKP sensor and visually inspect the teeth of the signal rotor through the CKP sensor aperture for damage, foreign material, or incorrect installation. |
| - | A DTC P0339 that sets while driving and checks OK may be caused by inadequate CKP sensor circuit shielding. Check that the CKP sensor circuit is properly shielded and that the drain wire is fastened securely to ground. |
| • | An intermittent malfunction may be caused by a fault in the CKP sensor electrical circuit. Inspect the wiring harness and the components for an intermittent condition. Refer to Intermittent Conditions . |
| • | Repair any electrical circuit faults that were found. Refer to Wiring Repairs in Wiring Systems. |
| • | The information included in the Freeze Frame data can be useful in determining the vehicle operating conditions when the DTC first set. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
-
This step determines whether the DTC P0339 is the result of a hard failure or an intermittent condition. If engine will not start, crank the engine over 3 consecutive ignition cycles (key ON - key OFF).
-
This step verifies the internal resistance of the crankshaft position sensor. A typical value at 23°C (74°F) is 2.1K ohms.
-
This step tests the CKP sensor output signal and electrical circuit to the PCM.
-
This step determines which half of the CKP sensor circuit is faulty.
-
This step inspects for a faulty signal rotor. Visually inspect the teeth of the signal rotor through the CKP sensor aperture for damage, foreign material, and mis-alignment.
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||
Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | ||||||||
2 | Are DTCs P0339 and P0340 both set? | -- | Go to Step 10 | Go to Step 3 | ||||||
Does the vehicle start and run? | -- | Go to Step 4 | Go to Step 5 | |||||||
4 |
Is DTC P0339 set? | -- | Go to Step 5 | Go to Diagnostic Aids | ||||||
Is the resistance within the specified range? | 1,630-2,740 ohms at -10 to +50°C (+14 to +122°F) or 2,065-3,225 ohms at 50-100°C (122-212°F) | Go to Step 6 | Go to Step 13 | |||||||
Was the AC voltage indicated while cranking within the specified range? | 1.4-1.6 V AC | Go to Step 14 | Go to Step 7 | |||||||
Was the AC voltage indicated while cranking within the specified range? | 1.4-1.6 V AC | Go to Step 9 | Go to Step 8 | |||||||
8 | Test for an open or a short in the CKP sensor input circuit. Refer to Wiring Repairs in Wiring Systems. Did you find and repair a condition? | -- | Go to Step 15 | Go to Step 11 | ||||||
9 | Repair the open in the CKP sensor ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 15 | -- | ||||||
10 |
Did you find and correct a condition? | -- | Go to Step 15 | Go to Step 14 | ||||||
Did you find and correct a condition? | -- | Go to Step 15 | Go to Step 12 | |||||||
12 |
Did you find and correct a condition? | -- | Go to Step 15 | Go to Step 13 | ||||||
13 | Replace the crankshaft position sensor. Refer to Crankshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- | ||||||
14 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- | ||||||
15 |
Does the DTC run and pass? | -- | Go to Step 16 | Go to Step 2 | ||||||
16 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |||||||
