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 CMP sensor inputs. The CKP sensor is also used to detect misfire and tachometer display. The CKP sensor signal circuit and the low reference circuits are connected directly to the ECM. The shielded ground circuit is connected to ground. The circuits between the CKP sensor and the ECM consists of the following circuits:
| • | A CKP sensor signal |
| • | A CKP sensor low reference |
| • | A shielded ground |
If the ECM detects an incorrect number of CKP pulses from the CKP sensor, DTC P0336 sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0336 Crankshaft Position (CKP) Sensor Performance
Conditions for Running the DTC
| • | The engine is running. |
| • | The number of extra or missing teeth is more than or equal to 2 per revolution. |
| • | DTC P0336 runs continuously once the above conditions are met. |
Conditions for Setting the DTC
| • | The ECM detects extra or missing CKP pulses. |
| • | The above condition is detected in 10 of 100 crankshaft rotations. |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the third consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 4 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Step | Action | Value | Yes | No | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector 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 | |||||||||||
2 | Attempt to start the engine Does the engine start and run? | -- | Go to Step 3 | Go to Step 4 | ||||||||||
3 |
Did the DTC fail this ignition? | -- | Go to Step 4 | Go to Intermittent Conditions | ||||||||||
4 |
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 5 | ||||||||||
5 |
Does the engine stumble or stall when moving the harnesses and connectors? | -- | Go to Step 8 | Go to Step 6 | ||||||||||
6 | Move the related harnesses and connectors at the CKP sensor connector. Does the engine stumble or stall when moving the harnesses and connectors? | -- | Go to Step 9 | Go to Step 7 | ||||||||||
7 | Measure the resistance from the ground circuit of the CKP sensor and the battery ground at the ECM side of the CKP sensor connector. Is the resistance less than the specified value? | 5 ohms | Go to Step 11 | Go to Step 14 | ||||||||||
8 | Test the CKP sensor circuits between the ECM and the CKP sensor connector for an intermittent condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 10 | ||||||||||
9 | Test the CKP sensor circuits for an intermittent condition between the CKP connector and the ECM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 11 | ||||||||||
10 | Test for an intermittent and for a for 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 17 | Go to Step 16 | ||||||||||
11 | Test for an intermittent and for a for poor connection at the CKP connector. 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 17 | Go to Step 12 | ||||||||||
12 |
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 17 | Go to Step 13 | ||||||||||
13 |
Important: If the reluctor wheel is also damaged, replace the CKP sensor and the crankshaft. Inspect the reluctor wheel for the following conditions:
Refer to Crankshaft and Bearing Cleaning and Inspection in Engine Mechanical - 2.0L (L34GMDAT). Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 15 | ||||||||||
14 | Repair the open or high resistance in the CKP sensor ground circuit. Did you complete the repair? | -- | Go to Step 17 | -- | ||||||||||
15 | Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- | ||||||||||
16 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- | ||||||||||
17 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 18 | ||||||||||
18 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||||||
