Crankshaft Position System Variation Not Learned
Table of contents
P0315 BUICK Possible Causes
- Crankshaft position (CKP) system variation learning
- Faulty Crankshaft Position (CKP)
- Crankshaft Position (CKP) sensor harness is open or shorted
- Crankshaft Position (CKP) sensor circuit poor electrical connection
How do I fix code P0315 BUICK?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- The crankshaft position (CKP) system variation learn procedure is done better with an scan tool, but if the Crankshaft Variation Relearn is not accessible through your scan tool (some truck applications 1998 & later), perform the relearn in the following manner:
- 1. Turn off all of the accessories. With the Air temperature sensor and Coolant temperature within 5 degrees (Centigrade) of each other, start the engine and let it idle in Park or Neutral for two minutes.
- 2. Accelerate the vehicle to 55 mph at part throttle. Cruise at 55 mph for 8- 10 minutes until the engine reaches operating temperature.
- 3. Cruise at 55 mph for another 5-6 minutes.
- 4. Decelerate to 45 mph without using the brakes, and maintain 45 mph for 1 minute.
- 5. Perform 4 deceleration cycles, without using the brakes, of 25 seconds each where no specific speed is necessary. Returning to 45 mph for 15 seconds in between deceleration cycles.
- 6. Accelerate to 55 mph and cruise for 2 minutes.
- 7. Stop the vehicle and idle for 2 minutes with the brake applied and the transmission in Drive (automatic trans.) or Neutral (manual trans.) with the clutch depressed.
Cost of diagnosing the P0315 BUICK code
The cost of diagnosing the P0315 BUICK code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Engine fails to start
- Engine runs rough
P0315 BUICK Description
The crankshaft position (CKP) system variation learn feature is used to calculate reference period errors caused by slight tolerance variations in the crankshaft, and the CKP sensor. The calculated error allows the engine control module (ECM) to accurately compensate for reference period variations. This enhances the ability of the ECM to detect misfire events over a wider range of engine speed and load.
The CKP system variation compensating values are stored in ECM memory after a learn procedure has been performed and the ignition switch is turned to the OFF position for at least 30 seconds . If the actual CKP variation is not within the CKP system variation compensating values stored in the ECM, DTC P0300 may set.
If the CKP system variation values are not stored in the ECM memory or a proper ECM power down does not occur after completing the CKP Learn Procedure, DTC P0315 sets.