P033E: Knock/Combustion Vibration Sensor D Circuit Intermittent

The knock sensor is a piezoelectric structure-borne sound sensor bolted to the engine block; the module evaluates its signal per cylinder and retards ignition when it detects knock. Sensor D is a fourth sensor on engines with four knock sensors (McLaren 12C V8, Ford's 2020–23 systems). With a fault the module retards ignition across the board as protection – noticeable loss of power and higher consumption. P033E reports brief dropouts of the sensor signal – loose contacts, a wire breaking with engine movement and heat, or a loose sensor. No manufacturer document with a threshold for this code was found; GM and Ford cover such faults with their circuit codes, so the description follows CARB's input monitoring requirement.

Symptoms

• Check engine light on
• Loss of power, sluggish response from ignition retard
• Higher fuel consumption

Most likely causes

• Loose contact, spread pins or corrosion in the connector
• Wire chafing only with engine movement or heat
• Sensor loose or wrongly torqued
• Sensor or engine module faulty

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the connector and wiring
2. Gently move the wiring with the engine running and watch whether the reading changes.
3. Check the mounting torque and seating according to the manufacturer
4. Check the octane rating of the fuel you use
5. Replace the sensor if the circuit is good

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P033E means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 3: Ignition and misfires
• 3E: Specific fault in that system

Frequently asked questions

Can I keep driving with code P033E?

You can drive in moderation without pushing the engine. If you hear knocking, avoid full-throttle acceleration.

What causes code P033E?

The most common causes are: loose contact, spread pins or corrosion in the connector; wire chafing only with engine movement or heat; sensor loose or wrongly torqued.

Related codes

• P033AKnock/Combustion Vibration Sensor D Circuit
• P033BKnock/Combustion Vibration Sensor D Circuit Range/Performance
• P033CKnock/Combustion Vibration Sensor D Circuit Low
• P032EKnock/Combustion Vibration Sensor C Circuit Intermittent
• P0324Knock/Combustion Vibration Control System Error

Sources

• law.cornell.edu: 13 CCR 1968.2
• bosch-mobility.com: product data sheet knock sensor

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.