Ethan brought SLA his Scion FRS for a check engine light. He did not notice any changes in drive-ability or a lack of performance.
We scanned the codes and found P0016, crank/cam position correlation-bank 1 sensor “A”. Our team learned that the VVT value for the passenger intake camshaft sprocket was out of the acceptable range. The ECM must see all 4 camshaft angle’s in sync with one another. The fault code points to a timing or “sync” issue on the passenger side, intake camshaft.
The vehicle was mildly modified, with only an aftermarket header and a “Flex Fuel” or E85 tune.
In order to visually inspect the engine’s mechanical timing, we had to remove the front timing cover. The cover is held on with an excess of 40 bolts, and sealed to the block with RTV sealant. After rotating the engine over by hand in order to line up the timing marks, we noticed that driver side, intake camshaft sprocket to be out of line or “time” with the engine’s timing marks. This told us the inner mechanism of the variable camshaft sprocket to be worn.
We replaced the trouble camshaft sprocket with a new, OEM sprocket and re-timed the engine. Reinstalled the front timing cover with new RTV sealant.
P0016 Fault Code
Due to this particular fault code, it can burn the “learned camshaft angle” memory into the ECM, requiring the ECM to be replaced. After replacing the faulty camshaft sprocket, the ECM will continue to see that incorrect camshaft angle, as it has learned that value. Sometimes, these learned values are unable to be cleared or reset. This ECM issue isn’t a cause of the faulty camshaft sprocket but more of a design flaw with the ECM’s construction.
Advice From The Experts – Check Engine Light
If your Check Engine Light comes on, bring to your Subaru specialists for proper diagnosis!