For 1990-2009 cars
Engine Controls Components
Cell 20: MAF, IAC, Knock Sensors
OBD II Symbol Description Notice

### Circuit Description

The PCM contains integrated Knock Sensor (KS) diagnostic circuitry. Input signals from the knock sensors are used to detect engine detonation, allowing the PCM to retard Ignition Control (IC) spark timing based on the amplitude and frequency of the KS signal being received. The knock sensors produce an AC signal under all engine operating conditions. The PCM calculates an average voltage of each sensors signal and takes an instantaneous signal voltage readings. The PCM uses the instantaneous signal voltage readings to determine the state of the knock sensor circuitry. If the knock sensor system is operating normally, the PCM should monitor instantaneous KS signal vooltage readings varying outside a voltage range above and below the calculated average voltage. If the PCM detects a knock sensor signal 2 signal voltage within the calculated average voltage range, DTC P0332 will set.

### Conditions for Running the DTC

• | No TP sensor, VSS, CKP, MAF or ECT sensor DTCs set.

• | Engine speed is between 1000 and 3000 RPM.

• | Throttle angle is greater than 15%.

• | Engine load is greater than 45%.

• | Engine coolant temperature is greater than 75°C (167°F).

• | Maximum system spark retard is less than 15 degrees.

• | System voltage is greater than 9 volts.

### Conditions for Setting the DTC

The PCM detects a Knock Sensor 2 signal voltage within the calculated average range.

### Action Taken When the DTC Sets

• | The PCM will not illuminate the Malfunction Indicator Lamp (MIL).

• | The PCM will store conditions which were present when the DTC set as Fail Records data only. This information will not be stored as Freeze Frame data.

• | The PCM will use a calculated spark retard value to minimize knock during conditions when knock is likely to occur. The calculated value will vary based on engine speed and load.

### Conditions for Clearing the MIL/DTC

• | A history DTC P0332 will clear after 40 consecutive warm-up cycles have occurred without a fault.

• | DTC P0332 can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.

### Diagnostic Aids

Check for the following conditions:

• | Poor connection at the PCM or Knock Sensor 2.

| Inspect knock sensor 2 and PCM connectors for backed out terminals, broken locks, and improperly formed or damaged terminals.

• | Misrouted harness.

| Inspect the knock sensor harness to ensure that it is not routed too close to high voltage wires such as spark plug leads.

Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

### Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

1. Ensures that the malfunction is present.

2. If sent here from symptoms, proceed with the diagnostic table.

#### DTC P0332 - Knock Sensor Circuit

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to the Powertrain On Board Diagnostic (OBD) System Check
2 | Important: If a mechanical engine knock can be heard, repair the engine mechanical problem before proceeding with this diagnostic. Refer to Engine Noise Diagnosis in Engine Mechanical.

1. Operate the engine within conditions specified in Conditions for Setting the DTC.
2. Using a scan tool, monitor Specific DTC info for DTC P0332 until the DTC P0332 test runs.

Does scan tool indicate DTC P0332 failed this ignition?

--

Go to Step 4

Go to Step 3

3 |

1. Turn ON the ignition switch, engine not running.
2. Review and record scan tool Fail Records data for DTC P0332.
3. Operate vehicle within Fail Records conditions.
4. Using a scan tool, monitor Specific DTC info for DTC P0332 until the DTC P0332 test runs.

Does the scan tool indicate DTC P0332 failed this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4 |

1. Disconnect the PCM and the Knock Sensor.
2. Check the KS circuit for opens and shorts to ground.
3. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Was problem found?

--

Go to step 7

Go to Step 5

5 |

1. Check the the KS signal circuit for a poor terminal connection at the knock sensor.
2. If a problem is found, repair as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Was problem found?

--

Go to Step 7

Go to Step 6

6 | Replace the knock sensor. Refer to Knock Sensor Replacement Is action complete? | -- | Go to Step 7 | --
7 |

1. Review and record Fail Records data
2. Clear DTCs.
3. Operate the vehicle within Fail Records conditions.
4. Using a scan tool, monitor Specific DTC info for DTC P0332 until the DTC P0332 test runs.

Does the scan tool indicate DTC P0332 failed this ign?

--

Go to Step 2

System OK