Diagnostic Instructions
DTC Descriptor
DTC 019: Crankshaft Position (CKP) Sensor Circuit
Circuit/System 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:
Conditions for Setting the DTC
| • | There are consecutive missing pulses of 10 or more. |
| • | The revolutions of the 58x signal is less than 65. |
| • | The DTC runs continuously once the above conditions are met. |
Diagnostic Aids
The following conditions could also set the DTCs:
| • | Physical damage to the CKP sensor or the reluctor wheel |
| • | Excessive play or looseness of the CKP sensor or the reluctor wheel |
| • | Improper installation of the CKP sensor or the reluctor wheel |
| • | Foreign material passing between the CKP sensor and the reluctor wheel |
| • | Excessive air gap between the CKP sensor and the reluctor wheel |
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
| • | Attempt to start the engine, observe the DTC information with a scan tool. DTC 019 should not set. |
| • | Move related harnesses/connectors of the CKP sensor and verify the engine does not stumble, stall, or change engine speed. |
Circuit/System Testing
Important: If the CKP sensor lead is damaged in any way, replace the CKP sensor.
- Ignition OFF, disconnect the harness connector of the crankshaft position (CKP) sensor.
- Ignition ON, verify that 1.5-2.0 volts is available on the signal circuit and the low reference circuit of the CKP sensor.
| ⇒ | If less than 1.5 volts, test the applicable circuit for a short to ground or an open/high resistance. If the circuits/connections test normal, replace the ECM. |
| ⇒ | If more than 2.0 volts, test the applicable
circuit for a short to voltage. If the circuits/connections test normal, replace the ECM. |
- If all circuits/connections test normal, test or replace the CKP sensor.
Component Testing
- Ignition OFF, disconnect the harness connector of the crankshaft position (CKP) sensor.
Important: If the CKP sensor lead is damaged in any way, replace the CKP sensor.
- Connect a DMM between the signal circuit and the low reference circuit of the CKP sensor.
- Test for 460-620 ohms between the signal circuit and low reference circuit.
| ⇒ | If the resistance is not within the specified range, replace the CKP sensor. |
- Disconnect the fuel pump relay.
- Set the DMM to the AC voltage scale.
- While cranking the engine, test for more than 1.4 ACV between the signal circuit and low reference circuit of the CKP sensor.
| ⇒ | If less than 1.4 ACV, replace the CKP sensor. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
