Circuit Description
The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor produces an AC voltage of different amplitude and frequency. The frequency depends on the velocity of the crankshaft, and the AC voltage output depends on the crankshaft position and battery voltage. The CKP sensor works in conjunction with a 58X reluctor wheel attached to the crankshaft. The engine control module (ECM) can synchronize the ignition timing, fuel injector timing, and spark knock control based on the CKP and the camshaft position (CMP) sensor inputs. The CKP sensor is also used to detect misfire and tachometer display. The CKP sensor circuits are connected directly to the ECM. The circuits between the CKP sensor and the ECM consist of the following circuits:
| • | The signal |
| • | The low reference |
| • | The shielded ground |
If the ECM detects less than 58 reference pulses, this DTC sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0337 Crankshaft Position (CKP) Sensor Circuit Low Duty Cycle
Conditions for Running the DTC
| • | The engine is cranking or running. |
| • | DTC P0337 runs continuously once the above conditions are met. |
Conditions for Setting the DTC
The ECM detects less than 58 reference pulses for 10 consecutive crankshaft revolutions.
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate after 3 consecutive trips with a fail. |
| • | The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records. |
| • | A history DTC is stored. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn OFF after 4 consecutive ignition cycles in which the diagnostic runs without a fault. |
| • | DTCs can be cleared by using the scan tool. |
| • | Disconnect the ECM battery feed for more than 10 seconds. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if the condition is current.
-
This step tests for an internal condition within the CKP sensor.
-
This step tests if the CKP sensor is capable of generating a signal.
-
The ECM supplies 1.8 volts to the CKP sensor circuit. If the voltage is not within range, this indicates there is a circuit or ECM condition.
-
The ECM supplies 1.8 volts to the CKP sensor circuit. If the voltage is not within range, this indicates there is a circuit or ECM condition.
-
This step is testing if the signal circuit and the low reference circuits of the CKP sensor are shorted together. If the DMM displays continuity, the circuits are shorted together.
Step | Action | Values | Yes | No | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connect End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||||||
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | |||||||||||
Does DTC P0337 fail this ignition? | -- | Go to Step 4 | Go to Step 3 | |||||||||||
3 |
Did the DTC fail this ignition? | -- | Go to Step 4 | Go to Intermittent Conditions | ||||||||||
Is the resistance within the specified range? | 460-620 ohms | Go to Step 5 | Go to Step 11 | |||||||||||
Is the voltage more than the specified value while the engine is cranking? | 1.4 ACV | Go to Step 6 | Go to Step 14 | |||||||||||
Is the voltage within the specified range? | 1.5-2.0 V | Go to Step 7 | Go to Step 9 | |||||||||||
Measure the voltage between the low reference circuit of the CKP sensor and a good ground with a DMM. Is the voltage within the specified range? | 1.5-2.0 V | Go to Step 8 | Go to Step 10 | |||||||||||
Does the DMM display OL? | -- | Go to Step 13 | Go to Step 15 | |||||||||||
9 | Test the signal circuit of the CKP sensor for the following:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 12 | ||||||||||
10 | Test the low reference circuit of the CKP sensor for the following :
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 12 | ||||||||||
11 | Test for an intermittent and for a poor connection at the CKP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 16 | ||||||||||
12 | Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 17 | ||||||||||
13 | Test for an intermittent and for a poor connection at the CKP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 16 | ||||||||||
14 |
Important: If the sensor lead is damaged in any way, DO NOT repair the lead.
Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 16 | ||||||||||
15 | Repair the short between the high reference circuit of the CKP sensor and the low reference circuit of the CKP sensor. Did you complete the repair? | -- | Go to Step 18 | -- | ||||||||||
16 | Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 18 | -- | ||||||||||
17 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 18 | -- | ||||||||||
18 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 19 | ||||||||||
19 | Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||||||
