Daewoo Matiz (2003 year). Manual - part 59

1F – 146  ENGINE CONTROLS

MAA1F170

DIAGNOSTIC TROUBLE CODE (DTC) – P0327 KNOCK SENSOR CIRCUIT FAULT

Circuit Description

The knock sensor(KS) system is used to detect engine
detonation, allowing the engine control module(ECM) to
retard ignition control spark timing based on the KS sig-
nal being received. The KS produces an AC signal so
that under a no knock condition the signal on the KS cir-
cuit measures about 0.007V AC. The KS signal’s ampli-
tude and frequency depend upon the amount of knock
being experienced. The ECM contains a non-replace-
able knock filter module called a signal-to-noise en-
hancement filter (SNEF) module. This filter module in
the ECM determines whether knock is occurring by
comparing the signal level on the KS circuit with the volt-
age level on the noise channel. The noise channel al-
lows the ECM to reject any false knock signal by
knowing the amount of normal engine mechanical noise
present. Normal engine noise varies depending on en-
gine speed and load. When the ECM determines that an
abnormally low noise channel voltage level is being ex-
perienced, a DTC P0327 will set.

Conditions for Setting the DTC

D

Knock sensor SPI bus in failure during 7 seconds.

D

The knock sensor voltage is below 0.2V.

D

Engine Coolant Temperature is higher than 80

°

C

(176

°

F).

D

Engine rpm is more than 2,500rpm.

D

Mass air flow is higer than 180mg/tdc.

Action Taken When The DTCs Sets

D

The Malfunction Indicator Lamp (MIL) will illuminate.

D

The ECM will record operating conditions at the time
the diagnostic fails. This information will be stored in
the Freeze Frame and Failure Records buffers.

D

A history DTC is stored.

Conditions for Clearing the MIL/DTC

D

The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.

D

A history DTC will clear after 40 consecutive warm-up
cycles without a fault.

D

DTC(s) can be cleared by using the scan tool.

DIAGNOSTIC AIDS

Check and correct any abnormal engine noise before
using the diagnostic table.

Any circuitry that is suspected as causing engine noise
complaint should be thoroughly checked for the follow-
ing conditions :

D

Backed-out terminals.

D

Improper mating.

D

Broken locks.

D

Improperly formed.

D

Damaged terminals.

D

Poor terminal-to-wire connections.

D

Physical damage to the wiring harness.

ENGINE CONTROLS  1F – 147

DTC P0327 – Knock Sensor Circuit

Step

Action

Value(s)

Yes

No

1

Perform an Euro On-Board Diagnostic (EOBD II)
System Check.
Is the system check complete?

–

Go to Step 2

Go to

“On-Board
Diagnostic

System Check”

2

1. Start the engine.
2. Install a scan tool.
3. Clear the Diagnostic Trouble Codes (DTCs).
4. Operate the vehicle within the Freeze Frame

conditions and conditions for setting the DTC as
noted.

Does the Malfunction Indicator (MIL) illuminate?

–

Go to Step 4

Go to Step 3

3

1. Turn the ignition switch ON, with the engine OFF.
2. Review the Freeze Frame data and note the

parameters.

3. Operate the vehicle within the Freeze Frame

conditions and conditions for Setting The DTC as
noted.

Does the Malfunction Indicator (MIL) illuminate?

–

Go to Step 4

Go to Step 12

4

Listen to the engine while raising and lowering the
engine speed.
Is a knock or audible noise present?

–

Go to Step 5

Go to Step 6

5

Repair the mechanical engine problem or a loose
bracket or component.
Is the repair complete?

–

Go to Step 12

–

6

1. Turn the ignition switch to lock.
2. Disconnect the engine control module(ECM).
3. With a digital voltmeter (DVM) connected to

ground, measure the resistance of the knock
sensor through the knock sensor signal circuit,
terminal 50.

Is the measured value within the specified value?

90–110K

Ω

Go to Step 7

Go to Step 9

7

Check for a poor connection at the ECM connector,
knock sensor (KS) signal circuit and repair as
necessary.
Is a repair necessary?

–

Go to Step 12

Go to Step 8

8

Replace the engine control module(ECM).
Is the replacement complete?

–

Go to Step 12

Go to Step 10

9

Check the KS electrical connector for a poor
connection and repair an necessary.
Is a repair necessary?

–

Go to Step 12

Go to Step 10

10

Check the KS signal circuit for an open or a low
voltage or voltage and repair as necessary.
Is a repair necessary?

–

Go to Step 12

Go to Step 11

11

Replace the KS.
Is the replacement complete?

–

Go to Step 12

–

1F – 148  ENGINE CONTROLS

DTC P0327 – Knock Sensor Circuit (Cont’d)

Step

Action

Value(s)

Yes

No

12

1. Using the scan tool, clear the DTCs.

D

Start the engine and idle at normal operating
temperature.

D

Operate the vehicle within the conditions for
setting this DTC as specified in the supporting
text.

Does the scan tool indicate that this diagnostic has
run and passed?

–

Go to Step 13

Go to Step 2

13

Check if any additional DTCs are set.
Are any DTCs displayed that have not been
diagnosed?

–

Go to

Applicable DTC

table

System OK

ENGINE CONTROLS  1F – 149

BLANK