Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's computer is saying that the power going to a sensor that helps control how the engine breathes is too high on one side of the engine.
The VVL (Variable Valve Lift) system adjusts the engine's valve lift for better performance and efficiency. This code indicates that the voltage supplied to the VVL sensors on Bank 2 is higher than expected.
The P1021 code is triggered when the powertrain control module (PCM) detects a higher than normal voltage level in the supply circuit for the Variable Valve Lift sensors on Bank 2. This could be due to an electrical fault such as a short circuit, a faulty sensor, or issues with the wiring or connectors.
• Check Engine Light is on
• Poor engine performance
• Reduced fuel efficiency
• Faulty VVL sensor
• Short circuit in the wiring
• Faulty PCM
VVL: Variable Valve Lift
PCM: Powertrain Control Module
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage.
• Test the VVL sensor for proper operation.
• Repair or replace damaged wiring.
• Replace the faulty VVL sensor.
• Reprogram or replace the PCM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Nissan Altima
• Infiniti G35
• Nissan Maxima
• Regularly inspect and maintain engine wiring.
• Ensure proper installation of sensors.
• Keep the engine bay clean to prevent electrical issues.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Regular maintenance can prevent such issues.
Check with the vehicle manufacturer for warranty coverage on engine sensors and electronic components.
P1021 is a code that has been associated with vehicles using advanced variable valve timing systems, particularly in Nissan and Infiniti models.
Moderate – While the vehicle may still operate, ignoring the issue can lead to reduced performance and efficiency.
Driving with a malfunctioning engine sensor can lead to increased emissions and may not comply with local environmental regulations.
• Engine at operating temperature
• Vehicle in a safe and stable condition
The VVL sensor is typically located on the engine cylinder head on Bank 2, which is the side of the engine opposite to Bank 1.
Q: Can I drive with a P1021 code?
A: You can drive, but it's not recommended as it may affect engine performance and efficiency.
Q: How do I clear the P1021 code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue is fixed, it should not return.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.