P0315

DTC P0315 SEGMENT TIME ACQUISITION INCORRECT

Component Location:

GENERAL DESCRIPTION
The Tooth Error Correction (TEC) Learn Algorithm determines engine-specific variation in crankshaft position sensing. The largest factor of variation is geometric tooth spacing although other factors, such as bearing run out, may also be present. Once TEC is learned, compensation factors are then calculated and used by the Misfire Diagnostic algorithm to improve the accuracy of engine position determinations.Tooth error correction factors are normally learned only once during the life of a vehicle. However, if a vehicle controller, engine crankshaft, target wheel, or crank sensor is replaced or serviced, tooth error correction factors must be re-learned. This can be performed in a service environment with serial data commands.

DTC DESCRIPTION
It is impossible to forge or machine a perfectly proportioned crankshaft wheel. Therefore, each crankshaft wheel produced will have minor variations in the spacing and/or width of its gear teeth.These variations (tooth error), if not compensated for, can cause false misfire detection. In order to account for tooth error, the tooth error correction algorithm measures the variation in crankshaft wheel teeth and calculates a compensation factor, which is applied to the reference periods when the misfire detection algorithm runs. This compensation factor is learned once, early in the life of the vehicle, and need never be learned again unless the crank wheel is replaced or the vehicle's PCM EEPROM or similar storage device is erased.

Checking tooth error correction under detecting condition, if the TEC is out of Threshold value, PCM sets P0315.

DTC Detecting Condition:

COMPONENT INSPECTION
1. Visually check CKPS and target wheel
1. IG"OFF"
2. Check CKPS and target wheel for deformation or damage visually
3. Is the above items normal ?

YES: Go to "Verification of Vehicle Repair" procedure.

NO: Substitute with a known - good PCM and check for proper operation. If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.

NOTE: There is a memory reset function on Scantool that can erase optional parts automatically detected and memorized by PCM. Before or after testing PCM on the vehicle, use this function to reuse the PCM on the others

VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions
4. Monitor that all readiness tests have been verified as Complete
5. Are any DTCs present?

YES: Go to the applicable trouble shooting procedure.

NO: System is performing to specification at this time.