Circuit Description
The DTC P1335 Crankshaft Position (CKP) Sensor Circuit diagnostic detects a loss of the crankshaft position sensor signal while the engine is running. The CKP sensor is a magnetic generator type sensor, producing an AC signal which 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 RPM and the crankshaft position. This reference signal along with the camshaft position sensor signal is used by the PCM to calculate the following:
| • | The ignition system timing |
| • | The fuel injection pulse width |
| • | The camshaft position phasing |
| • | The top dead center of piston travel |
Conditions for Running the DTC
The engine speed is more than 1,000 RPM.
Conditions for Setting the DTC
The crankshaft position (CKP) sensor input is not detected for over 50 ms while the engine is running.
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. |
| • | The DTC clears 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
A DTC P1335 can be the result of a defective reluctor wheel. Remove the crankshaft sensor and inspect the reluctor wheel through sensor hole. Check the reluctor wheel for porosity, nicks, dents, etc. and repair as necessary.
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 in the diagnostic table.
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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.
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This step checks whether DTC P1335 is the result of a hard failure or an intermittent condition. If engine will not start, crank engine over for 3 consecutive ignition cycles.
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This step is checking the internal resistance of the crankshaft position sensor and tests if the CKP sensors windings are opened or shorted.
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Using a DMM, measure the resistance of the wires from the PCM connector to the CKP connector on the harness side. If the DMM reads higher than 0.5 ohms, check for a short or high resistance in the circuit. Also, using a test light connected to ground with both the PCM and the CKP connectors unplugged, probe each connector terminal. This will determine if there is a short to battery voltage.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | ||
Does DTC P1335 set? | -- | Go to Step 3 | Go to Diagnostic Aids | |
Is the voltage within the specified value? | 985-1670 ohms at 50°C (122°F) or 1265-1890 ohms at 100°C (212°F) | Go to Step 4 | Go to Step 6 | |
Was a repair necessary? | -- | Go to Step 8 | Go to Step 5 | |
5 |
Was a repair necessary? | -- | Go to Step 8 | Go to Step 7 |
6 | Replace the crankshaft position sensor. Refer to Crankshaft Position Sensor Replacement . Is the action complete? | -- | Go to Step 8 | -- |
7 | Replace the PCM. Refer to Powertrain Control Module Replacement . Is the action complete? | -- | Go to Step 8 | -- |
8 |
Does the DTC run and pass? | -- | Go to Step 9 | Go to Step 2 |
9 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |
