Parts for your 2020 Holden Colorado-Knock sensor

2020 Holden Colorado knock sensor – fitted, functional, and worth keeping happy

Based on technical service literature, the 2020 Holden Colorado 2.8L Duramax (LWN) is fitted with a block‑mounted knock/combustion‑noise sensor and the engine control module uses its signal for fine control of injection timing and combustion noise. Relevant technical sources include: Holden/GM RG Colorado Service Manual (Engine Controls – 2.8L Diesel LWN) sections describing a “Combustion Noise (Knock) Sensor” and its circuit, GM Global Service Information that assigns DTCs P0324/P0325 to the LWN, and Bosch EDC17C59 diesel management documentation referencing a structure‑borne sound sensor for closed‑loop injection optimisation on common‑rail diesels.

On the 2020 Colorado, the knock sensor isn’t about petrol‑engine detonation, it’s a smart vibration microphone for the block. The ECU listens to that sensor to trim pilot and main injection, keep the clatter civil, protect the engine under dodgy fuel loads, and help emissions gear like the DPF behave. When the signal goes missing or noisy, the ECU tends to pull back on performance and may light the MIL.

As a service item, the knock sensor is essentially fit‑and‑forget, but it deserves a quick once‑over during routine work:

• Visual check: look for chafed wiring, oil contamination at the connector, or a loose sensor.
• Scan for codes: if P0324 or P0325 turns up, confirm wiring integrity and sensor signal before replacing parts.
• Mounting surface: if the sensor is removed, clean the block pad so it sits dead flat, no sealants or tape.
• Refit properly: tighten to the factory torque so it can “hear” correctly, over‑ or under‑torque dulls the signal.
• Quality parts: use a genuine or high‑quality equivalent, poor copies can skew frequency response.

Replacement is straightforward for a competent tech: disconnect the battery, access the sensor on the block (typically mid‑height on the intake side), unplug, remove, clean the mating face, install the new unit to spec, reconnect, clear any DTCs, and verify with a road test. If the vehicle arrived with extra rattle, sluggish step‑off, sootier exhaust, or higher fuel use, a restored knock‑sensor signal often helps the ECU bring back its usual crispness and refinement.

For workshop documentation, Holden’s RG Colorado Engine Controls – 2.8L Diesel (LWN) sections provide the component description, circuit diagram, and diagnostic flow for the knock/combustion‑noise sensor, while Bosch EDC17C59 literature explains why modern diesels use a structure‑borne sound sensor for closed‑loop combustion control.

Popular questions

Where is the knock sensor on a 2020 Holden Colorado 2.8?
It’s mounted to the engine block, generally on the intake side around mid‑block height. Access is often from underneath with the bash plate off. Exact location can vary slightly by market and model year, so a quick look at the RG Colorado workshop diagram makes life easier.

What are the symptoms of a faulty knock sensor on the Colorado?
Common signs include a check‑engine light (often P0324 or P0325), reduced power or conservative throttle response, harsher diesel clatter than usual, and a nudge up in fuel consumption. Because the ECU loses a key feedback signal, it plays it safe with injection timing until the issue is fixed.

Is it safe to keep driving with a bad knock sensor?
The vehicle will usually still run, but it’s not ideal. The ECU’s fallback strategy can bump fuel use, affect emissions controls, and allow more combustion noise. Best practice is to address wiring or sensor faults promptly to keep performance, economy, and refinement on song.