P06E4: Control Module Wake-up Circuit Performance

What it means

The control module wake-up circuit has a performance fault. The code does not by itself establish slow wake-up, missed events, or effects on cold starting or stop-start operation.

At a glance

• Usually lights the check-engine light

How it works

A control module's wake-up circuit brings the module out of its low-power state when the vehicle needs it. P06E4 means the monitored wake-up circuit is not performing as expected; the code alone does not identify a specific wake-up timing or prove that cold starting or stop-start operation is affected.

Common causes

Most likely first.

1. Wake-up circuit or connection fault
2. Control-module power or ground fault
3. Control-module fault

Symptoms

• Check engine light on
• Possible limp mode or no-start
• Multiple follow-up faults across modules
• Reset/relearn may be needed after repair

How to diagnose it

1. Save freeze-frame information and scan all modules for communication, supply-voltage, or wake-up-related codes to identify which module or circuit is involved.
2. Check the affected module's power and ground connections for looseness, corrosion, or damage.
3. Inspect the wake-up circuit wiring and connectors for breaks, pinched sections, corrosion, or pushed-back terminals.
4. Monitor wake-up command and circuit response with a scan tool or meter where the vehicle's service information specifies a test.
5. If the wiring and module supplies pass, test the control module's wake-up input or output using the manufacturer's diagnostic procedure.

Common fixes

• Clean and secure the affected module's power and ground connections.
• Repair damaged, open, or poorly connected wake-up circuit wiring.
• Repair corroded or pushed-back connector terminals.
• Repair or replace the affected control module if its wake-up circuit fails the specified tests.

Can I keep driving?

Driving guidance depends on which module is failing to wake; if the vehicle has starting, stalling, braking, steering, or warning-light problems, stop driving and arrange diagnosis. A wake-up fault can disrupt module communication or prevent a system from being available when needed.