Neon L4-2.0L DOHC (1996)
Timing Belt: Description and Operation
Timing Belt Skipped 1 Tooth or More Trouble Code
Name of Code:
Timing Belt Skipped 1 Tooth or More
When Monitored:
With the engine running, every 44ms an inhibit condition is looked for (wide open throttle, large change in rpm, large change in MAP, cold
engine, insufficient start to run time, rpm outside given windows). If an inhibit condition does not exist, the misalignment between the camshaft
and crankshaft is monitored.
Set Condition:
When the camshaft position sensor is offset from the crankshaft position sensor one tooth or more.
Theory of Operation:
The powertrain control module monitors the relationship between two signals, one from the camshaft sensor and one from the crankshaft sensor. If
the signals indicate misalignment, a trouble code matures and turns on the malfunction indicator lamp. A misalignment is detected by checking the
current alignment against the initial build value stored in the EEPROM of the PCM. This initial build value is established by the PCM when the
engine is running in a steady state operating mode. The initial build value is in a reset state at module manufacturing and is set by the PCM.
Possible Causes:
-
Valve timing out of specifications
-
Camshaft's relative position not relearned (DRB function) after one of the following have been serviced: cam, cam sprocket, timing belt,
tensioner, cylinder head, head gasket, crank sprocket, crankshaft, cylinder block or the PCM.
