P0332 on Chevrolet: How to Diagnose & Fix
Knock Sensor 2 Circuit Low Input (Bank 2)
3 Chevrolet models · 3 documented issues · $250-$900 repair
P0332 on Chevrolet by model: symptoms, diagnosis and fix
On Gen III Vortec V8s the two knock sensors sit in the lifter valley beneath the intake manifold, under a plastic cover. Water and debris collect in the valley and corrode the sensor connectors and wiring; the factory connectors also embrittle from heat. The result is an intermittent knock-sensor signal that sets P0327 (front sensor) and/or P0332 (rear sensor), illuminating the check engine light.
Common Symptoms
- Check engine light on
- P0327 or P0332 stored
- Occasional loss of power/timing pull
- Slight fuel economy drop
- Intermittent codes that return
How to Fix
Remove the intake manifold, replace both knock sensors (AC Delco 213-3521 / GM 12570125) AND the knock-sensor wiring harness (GM 12601822), reseal the valley cover, and add dielectric grease to the connectors. Replacing only the sensors without the harness often leaves the fault. Kits bundling both sensors, the harness, and an intake gasket set are widely sold.
Sources for this issue (1)
On 4.8L, 5.3L, and 6.0L GMT800 V8 trucks, the valley-mounted knock sensors and harness are prone to water intrusion from the cowl/intake area. Moisture corrodes the sensors or harness connectors, leading to false knock readings, a check engine light, and timing retard that can make the truck feel sluggish. This is one of the best-known early Silverado engine electrical issues and is heavily documented by owners and repair shops.
Common Symptoms
- check engine light
- reduced power or sluggish acceleration
- poor fuel economy
- intermittent spark knock timing retard
- engine runs normally but stores knock sensor codes
How to Fix
Diagnosis should confirm sensor circuit faults and inspect the harness and sensor wells for corrosion or standing water. Repair typically includes replacing both knock sensors, the sub-harness, intake gaskets, and the rubber seals/grommets, while cleaning the valley and addressing any water entry path. Using dielectric protection and updated sealing practices helps prevent repeat failures.
Sources for this issue (2)
On Gen III small-block V8s the two knock sensors sit down in a recessed valley UNDER the intake manifold. Water (rain, car washes, snow melt) collects in the recess and corrodes the sensors and their two-wire harness, setting P0327 (Bank 1 low) and/or P0332 (Bank 2 low), often together, illuminating the Check Engine light. The ECM then pulls timing, which can cost power and mpg. Because the sensors are buried, the repair is labor-heavy: the intake manifold has to come off.
Common Symptoms
- Check Engine light with P0327/P0332
How to Fix
Replace BOTH knock sensors AND both wiring harnesses (a partial repair usually returns the code). This requires removing the intake manifold, so replace the intake manifold gaskets at the same time.
Sources for this issue (3)
P0332 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0332 mean on a Chevrolet?
P0332 stands for "Knock Sensor 2 Circuit Low Input (Bank 2)." This code means the Engine Control Module detected a low-voltage (or low-amplitude) signal from Knock Sensor 2 on Bank 2 — the cylinder bank that does not contain cylinder 1. The knock sensor 'listens' for engine detonation (pinging) so the computer can retard ignition timing to protect the engine. P0332 sets when this sensor's signal is consistently lower than expected, suggesting the sensor, its wiring, or connection is faulty. To stay safe, the ECM may pull timing, which can slightly reduce power and fuel economy. On Chevrolet it is documented across 3 models: Suburban, Silverado 1500, Tahoe.
What are the most common causes of P0332?
The most common causes of P0332 are: Faulty knock sensor on Bank 2, Open or high-resistance wiring in the knock sensor circuit, Corroded or loose knock sensor connector, Poor ground for the knock sensor, Chafed or shorted sensor harness, Improper sensor torque/mounting (poor contact with the block), Faulty ECM/PCM knock sensor input. The specific cause varies by vehicle.
How much does it cost to fix P0332 on a Chevrolet?
Published repair estimates on Chevrolet range from $250 to $900 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.