How to replace the knock sensors How to replace the Engine Coolant Temperature (ECT) sensor on Chevrolet Trailblazer?

Knock sensors in the engine sense unusual vibration and diminish spark knock. They give AC output voltage that increases with the severity of the knock. The PCM receives the signal and retards timing to compensate for detonation. The 4.2L six-cylinder engine has two knock sensors, with sensor 1 located towards the front and sensor 2 towards the rear. Knock sensor system can be affected by premium or high octane fuel, thus creating false codes. To replace the knock sensors, disconnect the negative battery terminal, raise vehicle and secure on jackstands. Disconnect knock sensor electrical connector and remove sensor bolt. For V8 models from 2002 to 2004, remove intake manifold and detach grommets and electrical connector off valley cover. Take out knock sensors from engine block. For V8 models from 2005 and later, disconnect negative battery cable, raise vehicle and support on jackstands. Disconnect electrical connector and take out right side knock sensor from cylinder block. Repeat for left side.

Genuine Chevrolet Trailblazer Knock Sensor

Engine Knock Sensor

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6 Knock Sensors found

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Chevrolet Trailblazer Sensor,Knock
Part Number: 12589867
$63.12 MSRP: $131.06
You Save: $67.94 (52%)
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Product Specifications
- Other Name: SENSOR, Distributor (also Knock Sensor); Knock Sensor
- Replaces: 10456603
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2003-2004 Chevrolet Trailblazer | 4 DOOR, 4 DOOR EXT | 8 Cyl 5.3L
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Chevrolet Trailblazer Sensor Assembly, Knock
Part Number: 12623730
$13.41 MSRP: $25.30
You Save: $11.89 (47%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: SENSOR, Distributor (also Knock Sensor); Knock Sensor
- Replaces: 12570125
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2005-2009 Chevrolet Trailblazer | 4 DOOR, 4 DOOR EXT | 6 Cyl 4.2L, 8 Cyl 5.3L, 8 Cyl 6.0L
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Chevrolet Trailblazer Sensor,Knock
Part Number: 12567446
$25.81 MSRP: $48.68
You Save: $22.87 (47%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: SENSOR, Distributor (also Knock Sensor); Knock Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2003-2005 Chevrolet Trailblazer | 4 DOOR, 4 DOOR EXT | 6 Cyl 4.2L
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Chevrolet Trailblazer Sensor,Knock
Part Number: 24100388
$25.57 MSRP: $48.26
You Save: $22.69 (48%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: SENSOR, Distributor (also Knock Sensor); Knock Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2002 Chevrolet Trailblazer | 4 DOOR, 4 DOOR EXT | 6 Cyl 4.2L
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Chevrolet Trailblazer Sensor Assembly, Knock
Part Number: 12663209
$3.91 MSRP: $7.37
You Save: $3.46 (47%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Knock Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2021-2025 Chevrolet Trailblazer | 4 DOOR EXT, LEVEL II 4 DOOR EXTENDED, LEVEL III 4DOOR EXTENDED, LEVEL IV 4 DOOR EXTENDED, LEVEL V 4 DOOR EXTENDED | 3 Cyl 1.3L
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Chevrolet Trailblazer Sensor Assembly, Knock
Part Number: 55494828
$14.00 MSRP: $25.12
You Save: $11.12 (45%)
Product Specifications
- Other Name: Knock Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2021-2025 Chevrolet Trailblazer | 4 DOOR EXT, LEVEL II 4 DOOR EXTENDED, LEVEL III 4DOOR EXTENDED | 3 Cyl 1.2L

Chevrolet Trailblazer Knock Sensor

Chevrolet Trailblazer automobiles use the Knock Sensor that helps to determine the presence of knock within the engine, this is a phenomenon characterized by wrong ignition rhythm. This device informs the PCM that it is not be sending the optimal signals to the ignitions to control high detonation. Usually, knock sensors used in Chevrolet models are piezoelectric, which transforms those vibrations into electrical signals and means that pressure peaks, which signify knocking, can be monitored constantly. In the recent past, the Trailblazer has incorporated a very complex knock sensor that sets ignition from one cylinder to the other and controls boost pressure depending on engine architecture. This is so because it enables both optimum performance and protection of the engine irrespective of fuel quality. This way, the Chevrolet Trailblazer maintains the operation near the 'knock limit' on one hand contributing to the car's performance but on the other hand protecting the engine depending on the road conditions.

Each OEM Chevrolet Trailblazer Knock Sensor we offer is competitively priced and comes with the assurance of the manufacturer's warranty for the part. Furthermore, we guarantee the speedy delivery of your orders right to your doorstep. Our hassle-free return policy is also in place for your peace of mind.

Chevrolet Trailblazer Knock Sensor Parts Questions & Experts Answers

Sensor,Knock
12589867
Q: How to replace the knock sensors How to replace the Engine Coolant Temperature (ECT) sensor on Chevrolet Trailblazer?
A: Knock sensors in the engine sense unusual vibration and diminish spark knock. They give AC output voltage that increases with the severity of the knock. The PCM receives the signal and retards timing to compensate for detonation. The 4.2L six-cylinder engine has two knock sensors, with sensor 1 located towards the front and sensor 2 towards the rear. Knock sensor system can be affected by premium or high octane fuel, thus creating false codes. To replace the knock sensors, disconnect the negative battery terminal, raise vehicle and secure on jackstands. Disconnect knock sensor electrical connector and remove sensor bolt. For V8 models from 2002 to 2004, remove intake manifold and detach grommets and electrical connector off valley cover. Take out knock sensors from engine block. For V8 models from 2005 and later, disconnect negative battery cable, raise vehicle and support on jackstands. Disconnect electrical connector and take out right side knock sensor from cylinder block. Repeat for left side.