Isuzu 1999 RODEO Workshop Manual page 957

6E1–330 RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
cycle of the vehicle unless the crank sensor to crankshaft
relationship is disturbed. Removing a part for inspection
and then reinstalling the same part is considered a
disturbance. A fully warmed up engine is critical to
learning the variation correctly. If a valid learn occurs, no
other learns can be completed that ignition cycle. If the
engine cuts out before the specified learn procedure
engine speed or at normal fuel cut–off RPM. The PCM is
not in the learn procedure mode. Review the Crankshaft
Position Sensor Tooth Error Correction (TEC) Procedure
and re–enable the learn procedure. Verify that the Tech 2
says "Test in Progress."
Excessive Crankshaft Variation Symptom
Tech 2 Display
Factors out of range
Opposing factors out of
range
Sum out of range
Crank pulse count error
Possible Causes
Reluctor wheel–matching
quality, run out, incorrect
air gap
Disturbance–noise on
crank sensor circuit,
reattempt the Learn
procedure
Engine too cold,
reattempt the Learn
Procedure
Crank or Cam sensor
DTCs set–Repair first
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart:
1. The Powertrain OBD System Check prompts the
technician to complete some basic checks and store
the freeze frame and failure records data on the
Tech 2 if applicable. This created an electronic copy
of the data taken when the fault occurred. The
information is then stored on the Tech 2 for later
reference.
2. Engine temperature if critical to properly learn the
Crankshaft Position Sensor Tooth Error Correction
(TEC). Failure to properly warm the engine before
performing this procedure will result in an inaccurate
measurement of the Crankshaft Position Sensor
Tooth Error Correction (TEC). The PCM learns this
variation as the engine is decelerating and then
allows engine control to be returned to the operator.
All accessories must be turned OFF when learning
the Crankshaft Position System angle variation. If
the A/C is not disabled when the learn procedure is
enable, the PCM will disable the A/C. When the
PCM is ready to allow the learn procedure to run,
the Tech 2 will display "Test in Progress."
3. If after the specified number attempts the PCM
cannot learn the crankshaft position Sensor Tooth
Error Correction (TEC) then the variation is too
large and no variation problem is corrected.
4. Being unable to learn the Crankshaft Position
Sensor Tooth Error Correction (TEC) indicates that
the variation is out of range. Using the Excessive
Crankshaft Variation Trouble shooting will help to
diagnose the area where the problem lies.