Diagnostic Instructions
DTC Descriptors
DTC 44: Knock Sensor (KS) 1 or 2 System Inactive
Circuit/System Description
The knock sensor (KS) system enables the engine control module (ECM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The ECM monitors 2 separate KS, one on each
side of the engine block. Each KS produces an AC voltage that varies, depending on the vibration levels detected during engine operation. The ECM receives the KS signal through 2 isolated signal circuits for each KS. The ECM adjusts the spark timing based on
the amplitude and frequency of each KS signal.
Diagnostic Aids
The following conditions could also set this DTC:
| • | 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. |
| • | The KS must be clear of hoses, brackets, and engine electrical wiring. |
| • | An electromagnetic interference (EMI) condition on the shielded ground circuit |
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Engine Control Module Connector End Views
Electrical Information Reference
Scan Tool Reference
Engine Control Module Scan Tool Information
Circuit/System Verification
Engine idling, observe the DTC information with a scan tool. DTC 44 should not set.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate KS.
- Ignition ON, test for 4.8-5.2 volts between the signal circuit and ground.
| ⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
- If all circuits test normal, replace the KS sensor.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
