Diagnostic Trouble Code (Dtc) P1381; Data Fault - Isuzu 1999 RODEO Workshop Manual

6E1–334 RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
DIAGNOSTIC TROUBLE CODE (DTC) P1381 ABS ROUGH ROAD CLASS 2
Circuit Description
The PCM identifies an engine misfire by detecting the
variations in crankshaft speed. The crankshaft speed
variations can also occur when a vehicle is operated over
a rough surface. The ABS (Anti–Lock Brake System) can
detect when the vehicle is on a rough surface based on
the wheel acceleration/deceleration data supplied by
each wheel speed sensor. The EBCM (Electronic Brake
Control Module) over the Class 2 serial data line sends
this information to the PCM. The PCM then uses this
information in order to determine if the crankshaft
variations are being caused by an actual engine misfire or
from being driven on a rough surface. DTC P1381 is a
type D code.
Conditions for Setting the DTC
f A DTC P0300–P0304 has been set.
f The vehicle speed is greater than 1 mph (2 km/h).
f The Manifold Absolute Pressure (MAP) is below 99.7
kPa.
f The engine speed is below 3406 RPM.
f The PCM has not received any ABS information for 2.5
seconds.
Action Taken When the DTC Sets
f The PCM records the operating conditions at the time
the diagnostic fails. The Failure Records buffers stores
this information.
SERIAL DATA FAULT
f A history DTC is stored.
f The PCM will not illuminate the Malfunction Indicator
Lamp (MIL).
Conditions for Clearing the DTC
f A history DTC clears after 40 consecutive warm up
cycles without a fault.
f The Tech 2 can clear the DTC.
Diagnostic Aids
The setting of this DTC indicates that a misfire was
detected and that the PCM could not determine if the
detected misfire was true or due to operating the vehicle
on a rough surface. A misfire can be a true misfire with or
without setting this DTC. Check the EBCM for poor
connections at the Class 2 serial data terminals. Be sure
no true misfire exists after repairing the cause of this DTC.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart:
1. The Powertrain OBD System Check indicates that a
misfire was detected and that the PCM could not
determine if the detected misfire was true or due to
operating the vehicle on a rough surface. A misfire
can be a true misfire with or without setting this
DTC. Check the EBCM for poop connections at the
Class 2 serial data terminals. Be sure no true
misfire exists after repairing the cause of this DTC.
014RX002