Circuit Description
The crankshaft position sensor is a hall-effect type sensor that monitors crankshaft position and speed. There are four teeth 90 degrees apart on the front of the crankshaft sprocket that induce a pulse in the sensor which is transmitted to the PCM. There is a physical one to one correspondence between the pump cam and crankshaft.
Conditions for Setting the DTC
| • | The PCM performs this DTC diagnostic continuously. |
| • | The number of consecutive missing crank pulses are greater than or equal to 8. |
| • | All diagnostic set conditions met for 2 seconds. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) on the first consecutive drive trip that the diagnostic runs and fails. |
| • | The Freeze Frame records the operating conditions at the time of failure and updates the Failure Records. |
| • | The PCM will activate Back Up fuel. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL off after three consecutive trips without a fault condition. |
| • | A History DTC will clear after forty consecutive warm up cycles that the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from start up coolant temperature and engine coolant temperature exceeds 71°C (160°F) that same ignition cycle. |
| • | The use of a scan tool. |
Diagnostic Aids
When the PCM is in backup fuel, long crank times, fast idle and poor performance conditions will exist. Check for a good connection at crankshaft position sensor and at the PCM. Many intermittent problems are caused by poor electrical connections or wiring. When attempting to diagnose an intermittent problem, always begin by trying to reproduce the conditions under which the failure occurs. This usually involves raising the engine to a higher temperature or operating it near RPM that the problem occurs. Since heat and vibration are often the cause of an intermittent, this may bring out the failure.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step will determine if DTC P0335 is the result of a hard failure or an intermittent condition.
-
This step checks the 5 volt reference circuit (the 5 volt reference may vary slightly).
-
This step checks the ground circuit.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing any DTCs, use the scan tool Capture Info to save freeze frame and failure records for reference, as the scan tool loses data when using the Clear Info function. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Does the scan tool display the specified value? | 8 | |||
3 | The DTC is intermittent. If no additional DTCs are stored, refer to the applicable DTC Tables first. Are any additional DTCs stored? | -- | Go to applicable DTC | Go to Diagnostic Aids |
Is the voltage within the specified range? | 4.8-5.2V | |||
Probe the sensor ground circuit with a test lamp connected to B+. Is the test lamp ON? | -- | |||
6 |
Is the voltage within the specified value? | 4.2-4.5V | ||
7 | Is the voltage more than the specified value? | 4.2-4.5V | ||
8 |
Was a repair performed? | -- | ||
9 |
Was a repair performed? | -- | ||
10 | Check the CKP 5 volt reference circuit for a proper connection at the PCM and replace the terminal if necessary. Did the terminal require replacement? | -- | ||
11 |
Was a repair performed? | -- | ||
12 |
Is there voltage present on the CKP sensor signal circuit? | -- | ||
13 | Repair the short to voltage on the CKP sensor signal circuit. Is the action complete? | -- | -- | |
14 | Check the CKP signal circuit for a proper connection at the PCM and replace the terminal if necessary. Did the terminal require replacement? | -- | ||
15 | Replace the Crankshaft position sensor. Refer to Crankshaft Position Sensor Replacement . After replacing the sensor, the PCM must be programmed with a new TDC Offset. Refer to Fuel Injection Pump Top Dead Center Offset Adjustment . Is the action complete? | -- | -- | |
16 |
Important: The new PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | |
17 |
Does the scan tool indicate the diagnostic Passed? | -- | ||
18 | Does the scan tool display any additional undiagnosed DTCs? | -- | Go to applicable DTC | System OK |
