Replace both crank sensors a and b, after this it is recommended to perform the crankshaft variation relearn which can only be performed with a scan tool. Going without the relearn can range from not noticeable, to a check engine light P1336.
Here is a description to explain.
The crankshaft position system variation learning feature is used in order to calculate the reference period errors caused by slight tolerance variations in the crankshaft, and in the crankshaft position sensors. The calculated error allows the powertrain control module (PCM) to accurately compensate for reference period variations. This enhances the ability of the PCM to detect misfire events over a wider range of engine speed and load.
The PCM stores the crankshaft position system variation values after a learn procedure has been performed. DTC 1336 set indicates that the crankshaft position system variation values have not been stored in the PCM and the crankshaft position system variation learn procedure must be performed. The learn procedure is required after the following service procedures have been performed, regardless of whether DTC P1336 is set:
" PCM replacement
" PCM reprogramming
" Engine replacement
" Crankshaft replacement
" Crankshaft position sensor replacement
" Any engine repair that disturbs the crankshaft-to-crankshaft position sensor relationship
Saturday, June 27th, 2009 AT 10:29 AM