For 1990-2009 cars

### Circuit Description

The ECM employs an internal module in order to continuously monitor the knock sensor control circuit. The KS module contains the circuitry that allows the ECM to utilize the KS signals and diagnose the KS sensors and circuitry. The KS module is not a replaceable component. If the ECM detects a fault in the ability of the KS module to sample these signals, this DTC will set.

### Conditions for Running the DTC

• | Tested continuously

• | The engine coolant temperature (ECT) is more than 40°C (104°F).

### Conditions for Setting the DTC

The ECM detects a fault in the internal knock sensor module.

### Action Taken When the DTC Sets

The ECM will not illuminate the malfunction indicator lamp (MIL).

### Conditions for Clearing the MIL/DTC

• | The ECM turns OFF the MIL after three consecutive drive trips that the diagnostic runs and passes.

• | A History DTC clears after forty consecutive warm-up cycles in which no failures are reported by this diagnostic or any other emission related diagnostic.

• | The ECM battery voltage is interrupted.

• | The scan tool clears the MIL/DTC.

#### DTC P1602 - Knock Sensor (KS) Module Circuit

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Important: This vehicle is equipped with a theft deterrent system that interfaces with the Engine Control Module (ECM). Program the new ECM with the frequency code of the theft deterrent module that is currently on the vehicle. Replace the ECM. Refer to Engine Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 3

--

3 |

1. Using the scan tool, clear the DTCs.
2. Start the engine.
3. Allow the engine to idle until the engine reaches the normal operating temperature.
4. Select DTC and the Specific DTC function.
5. Enter the DTC number that was set.
6. Operate the vehicle within the Conditions for Running this DTC until the scan tool indicates that the diagnostic Ran.

Does the scan tool indicate that the diagnostic Passed?

--

Go to Step 4

Go to Step 2

4 | Does the scan tool display any additional undiagnosed DTCs? | -- | Go to the applicable DTC table | System OK