U3021

Control Module Wake-up Circuit B Performance

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$17–89 (est.)

Symptoms

Difficulty starting the engine
Periodic shutdown of electronic systems
Check Engine Light Is On
Unstable operation of on-board electronics
Errors in other modules

Causes

Open or short circuit in wake-up circuit
Oxidation of connector contacts
Faulty wake up relay
Wiring harness damage
Internal control unit fault

How to Fix

Check the integrity of the wake-up circuit wiring
Clean connector contacts from oxidation
Check relay functionality
Scan other modules for errors
If necessary, replace the control unit

Related codes

U3000 U3001 U3022