U3521

High Voltage System Interlock Circuit F

Severity

🔴 High

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$56–222 (est.)

Symptoms

Check Engine light comes on
Reduced vehicle power
Complete loss of traction (in some cases)
Error message on display
Inability to start the engine (for hybrids)

Causes

Open circuit in the locking circuit
Short circuit
Lock sensor malfunction
Problems with high voltage relay
Control module malfunction

How to Fix

Check the integrity of the locking circuit
Check connections and connectors
Test blocking sensors
Check the operation of the high-voltage relay
Diagnose the control module
Repair only from an authorized dealer

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