Diagnostic Trouble Code (Dtc) P0325 Knock Sensor (Ks) Circuit Malfunction - Isuzu 1999 RODEO Workshop Manual

DIAGNOSTIC TROUBLE CODE (DTC) P0325 KNOCK SENSOR (KS) CIRCUIT
Circuit Description
The knock sensor (KS) system is used to detect engine
detonation. The knock sensor produced an AC voltage
signal. The knock sensor sends this signal to the PCM.
The amplitude and the frequency of the AC voltage signal
depends upon the knock level being detected. The PCM
will then retard the spark timing based on the signals from
the Knock Sensor. DTC P0325 is a type B code.
Conditions for Setting the DTC
f Engine run time is greater than 10 seconds.
f No P0327 Diagnostic Trouble Code set.
f Engine speed is above 2500 rpm.
All the above mentioned conditions are met, and the
following conditions are met for 8.75 seconds within a 10
second monitoring period:
f Any of the four A/D voltages exceeds 1.5625 Volts.
f Instantaneous A/D delta Voltage falls below 0.019531
Volts.
Action Taken When the DTC Sets
f The Malfunction Indicator Lamp (MIL) will illuminate
the second time the fault is detected.
f The PCM will record operating conditions at the time
the diagnostic fails.
f A history Diagnostic Trouble Code is stored.
RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
MALFUNCTION
f The PCM will use a calculated spark retard value in
order to minimize the knock during the conditions when
the knock is likely to occur. The calculated value will
vary based on the engine speed and load.
Conditions for Clearing the MIL/DTC
f The MIL will turn off after 3 consecutive ignition cycles
in which the diagnostic runs without a fault.
f A history Diagnostic Trouble Code will clear after 40
consecutive warm up cycles without a fault.
f A Tech 2 can clear the Diagnostic Trouble Codes.
Diagnostic Aids
Correct any abnormal engine noise before using the
diagnostic table.
Check for an open ignition feed circuit.
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 data and failure records data on
the Tech 2 if applicable. This creates an electronic
copy of the data taken when the malfunction
occurred. The information is then stored on the
Tech 2 for later reference.
6E1–211
D06RX051