11 Timing Belt Skipped 1 Tooth or More - (P 1390)

11 TIMING BELT SKIPPED 1 TOOTH OR MORE - (P 1390)

The 2.0L engine doesn't have broken belt valve clearance. Therefore, if the camshaft were allowed to be out of synchronization with the crankshaft, the valves might interfere with the pistons. The Powertrain Control Module (PCM) uses voltage signals generated by the cam (pin 26) and crank (pin 25) sensors to determine engine synchronization. If these signals become out of sync, not only may engine damage occur, but an increase of emissions and decrease of performance will occur.

ENABLING CONDITIONS
The following conditions must be met before the Cam/Crank Timing signal can be tested:

- Engine RPM must be between 575 and 960 (automatic transaxle), or between 1,055 and 4,000 (manual transaxle)
- Vehicle must be running at a steady state based upon information from the Throttle Position Sensor (TPS) and Manifold Absolute Pressure (MAP) sensor.
- Engine coolant temperature must be at least 170°F
- 61 seconds have elapsed since the start-to-run transfer

PENDING
The Cam/Crank Timing Diagnostic Trouble Code (DTC) will not be monitored if there is a malfunction with the CMP and/or CKP sensors.

The PCM monitors the 69° edges of the crankshaft from the CKP sensor. It also monitors the falling edges of the CMP sensor. The angle at which the two sensors are during the initial build of the vehicle is loaded into an EEPROM. The DTC is set if the angle between the CMP and CKP sensors exceed a pre-programmed amount. (Nominally, the starting angle will be 30°; the minimum angle is 8°; the maximum angle is 56°.)

The Cam/Crank Timing test runs continuously once the enabling conditions have been met. The MIL illuminates and the DTC is stored if the angle between the CMP and CKP have exceeded the threshold.

This malfunction could possibly be caused by problems with any of the following components:

- Timing belt (skipped at least one tooth)

The Cam/Crank angle is loaded into the EEPROM at the assembly plant. Manufacturing tolerances may cause the angle to be slightly different than production after certain components have been replaced. The following components, when replaced, require the use of the DRB III scan tool to erase the EEPROM and allow the EEPROM to learn the new angle:

- Camshaft
- Cylinder Head
- Cylinder Block
- CMP Sensor
- CMP Sensor Target
- PCM
- Water Pump

WARNING: If the timing belt has been incorrectly installed, and the PCM has had it's EEPROM erased, the PCM learns an incorrect angle and can not identify the camshaft being out of synchronization with the crankshaft.