ENGINE DRIVEABILITY AND EMISSIONS
6E–169
DIAGNOSTIC TROUBLE CODE (DTC) P0327 KNOCK SENSOR (KS) CIRCUIT
LOW INPUT
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The ECM uses the Knock Sensor (KS) in order to detect
engine detonation. This allows the ECM to retard the
Ignition Control (IC) spark timing based on the KS signal
the ECM receives. The knock sensors produce an AC
signal that rides on the 1.3 volts DC. The signal’s
amplitude and frequency are dependent upon the
amount of the knock being experienced.
The ECM determines whether the knock is occurring by
comparing the signal level on the KS circuit with a
voltage level on the noise channel. The normal engine
noise varies depending on the engine speed and load.
Then the ECM determines that an abnormally high
noise channel voltage level is being experienced, a
Diagnostic Trouble Code P0327 sets.
Diagnostic Aids
Check for the following conditions:
A poor connection at the ECM. Inspect the knock
sensor and the ECM connectors for: , broken locks,
improperly formed or damaged terminals.
• Backed out terminals
• Broken locks
• Improperly formed or damaged terminals
Also, check the wiring harness for: shorts to ground,
shorts to battery positive, and open circuits.
• A misrouted harness. Inspect the knock sensor
harness in order to ensure that it is not routed too
close to high voltage wires such as spark plug leads.
Code
Type
DTC Name
DTC Setting Condition
Fail-Safe (Back Up)
P0327
A
Knock Sensor Circuit
1. No DTC relating to MAP sensor.
2. Engine coolant temperature is more than
50°C.
3. Engine speed is more than 1600rpm.
4. Knock sensor harness short to ground or
short to voltage circuit.
ECM retards ignition timing 4°C.
µP
0.5
GRY
J1-27
+5V
µP
µP
5Volts
Reference
Knock
Sensor
0.5
YEL
0.5
WHT/
BLU
J1-7
0.5
BLU/
PNK
J1-32
0.5
BLK/
YEL
J1-15
J1-3
Engine
Coolant
Temperature(ECT)
Sensor
Throttle
Position Sensor
Knock Filter
Module
Engine
Control
Module
(ECM)