Diagnostic Trouble Code (Dtc) P0351 Ignition Coil "A" Primary/Secondary Circuit Malfunction - Isuzu 1999 RODEO Workshop Manual

6E1–228 RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
DIAGNOSTIC TROUBLE CODE (DTC) P0351 IGNITION COIL "A" PRIMARY/
Circuit Description
The ignition control circuit provides a zero volt or a 5 volt
signal to the ignition control module. The normal circuit
voltage is zero volts. When the module receives the 5 volt
signal from the powertrain control module (PCM), it
provides a ground path for the B+ voltage supplied to the
ignition primary coil. When the PCM turns off the 5 volts to
the module, the module will remove the ground path of the
ignition primary coils; causing the magnetic field
produces a voltage in the secondary coils which fires the
spark plug.
The circuit between the PCM and the ignition control
module is monitored for an open circuit, short to voltage,
and short to ground. When the PCM detects a problem in
the ignition control circuit, it will set DTC P0351. DTC
P0351 is a type A code.
Conditions for Setting the DTC
f Ignition ON.
f Output voltage is not equal to 5 volts when output is
ON.
f Output voltage is not equal to 0 volt when output is
OFF.
f Twenty test failures within 40 samples of continuous
circuit monitoring.
SECONDARY CIRCUIT MALFUNCTION
Action Taken When the DTC Sets
f The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
f The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
f The PCM will turn the MIL OFF on the third consecutive
trip cycle during which the diagnostic has been run and
the fault condition is no longer present.
f A history DTC P0351 will clear after 40 consecutive
warm–up cycles have occurred without a fault.
f DTC P0351 can be cleared by using the Scan Tool's
"Clear Info" function.
Diagnostic Aids
Check for the following conditions:
f Poor connection at the PCM – Inspect the harness
connectors for backed–out terminals, improper
mating, broken locks, improperly formed or damaged
terminals, and poor terminal–to–wire connections.
f Damaged harness – Inspect the wiring harness for
damage; Open circuits, shorts to ground, or shorts to
Voltage. If the harness appears to be OK, observe the
Tech 2 display related to DTC P0351 while moving the
connector and wiring related to the ignition system. A
change in the display will indicate the location of the
fault.
D06RX054