P06E4
Control Module Wake-up Circuit Performance
The wake-up circuit that brings the ECU out of standby on key-on or bus activity does not behave as expected - module slow to wake or wake events missed. Affects cold-start time and stop-start operation.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Common causes
Ordered by how often each turns out to be the cause.
- Wake-up pin response driftedCommon
Parts involved
- ECU Wakeup Circuit
P06E4 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.