Chevrolet Sonic Repair Manual: Knock Sensor System Description
- Circuit/System Description
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The knock sensor 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 uses the knock sensor system to test for abnormal engine noise that may indicate detonation, also known as spark knock.
- Sensor Description
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This knock sensor system uses one or two flat response dual-wire sensors. The sensor uses piezo-electric crystal technology that produces an alternating current (AC) voltage signal of varying amplitude and frequency based on the engine vibration or noise level. The amplitude and frequency are dependant upon the level of knock that the knock sensor detects. The ECM receives the knock sensor signal through 2 isolated signal circuits.
If the ECM has determined that knock is present, it will retard the ignition timing to attempt to reduce the knock. The ECM is capable of controlling spark retard on an individual cylinder basis. The ECM will always try to work back to a zero compensation level, or no spark retard. knock sensor diagnostics are calibrated to detect faults with the knock sensor circuitry inside the ECM, the knock sensor wiring, or the knock sensor voltage output. Some diagnostics are also calibrated to detect constant noise from an outside influence such as a loose/damaged component or excessive mechanical engine noise.
Knock Sensor Replacement
Knock Sensor Replacement
Callout
Component Name
Preliminary Procedures
Disconnect battery negative cable. Refer to
Battery Nega ...
Heated Oxygen Sensor Replacement - Sensor 1
Heated Oxygen Sensor Replacement - Sensor 1
Callout
Component Name
Warning: In order to avoid being burned, do not service the ...
Other materials:
Using the Tire Sealant and Compressor Kit to Temporarily Seal and Inflate a
Punctured Tire
When using the tire sealant and compressor kit during cold temperatures, warm
the kit in a heated environment for five minutes. This will help to inflate the
tire faster.
If a tire goes flat, avoid further tire and wheel damage by driving slowly to
a level place. Turn on the hazard warning fl ...
Sunroof Switch Replacement
Sunroof Switch Replacement
Callout
Component Name
Preliminary Procedure
Remove the dome lamp bezel. Refer to Dome Lamp Bezel Replacement.
1
Sunroof Switch
Procedure
Disconnect electrical conn ...
Active sound enhancement
NOTE:
To ensure the active sound enhancement system in the Nissan Armada operates
at its best performance, follow these important guidelines:
Do not block or cover the speakers, as this may distort or reduce sound
quality.
Avoid modifying or replacing the original speaker components inst ...
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