• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Knock Sensor Signal | P0327, P0328, P0332, P0333 | P0325, P0330 | P0327, P0328, P0332, P0333 | P0326 |
The knock sensor (KS) system enables the control module to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The sensors are located below each cylinder head on the engine block. The KS produces an AC voltage signal that varies depending on the vibration level during engine operation. The control module adjusts the spark timing based on the amplitude and the frequency of the KS signal. The control module receives the KS signal through 2 isolated signal circuits. The control module learns a minimum KS noise level at idle and uses calibrated values for the rest of the RPM range. The control module should monitor a normal KS signal within the noise channel.
This DTC runs continuously when the engine speed is greater than 1,800 RPM, and the manifold absolute pressure (MAP) is greater than 55 kPa.
This DTC runs continuously when the ignition is ON or the engine is running.
The control module has detected an internal circuitry fault.
The KS signal circuits are open or shorted together for 5 seconds.
• | The KS signal indicates an excessive engine knock is present. |
• | The ECM has commanded the spark retard to a value, which is more than the calibrated value, for a specific engine load and speed. |
• | The above conditions exist for more than 5 seconds. |
The KS signal circuits are shorted to voltage or ground.
DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332 and P0333 are Type B DTCs.
DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332 and P0333 are Type B DTCs.
• | Inspect the KS for physical damage. A KS that is dropped or damaged may cause a DTC to set. |
• | Inspect the KS for proper installation. A KS that is loose or over torqued may cause a DTC to set. The KS should be free of thread sealant. |
• | The KS mounting surface should be free of burrs, casting flash, and foreign material. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
• | If DTCs P0325, P0327, P0328, P0330, P0332 and P0333 are also set, perform those diagnostics first. |
• | This DTC indicates an internal control module circuitry failure. Replace the ECM. |
• | The KS signal circuit, terminal A |
• | The KS signal circuit, terminal B |
⇒ | If less than the specified range, test the circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM. |
⇒ | If greater than the specified range, test the circuits for a short to voltage. If the circuits test normal, replace the ECM. |
• | If DTC P0335 or P0336 are also set, diagnose those DTCs first. |
• | Inspect for a loose or broken vehicle accessory or accessory bracket. |
• | Inspect for excessive engine mechanical noise. |
Important: DO NOT tap on plastic engine components.
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming. |