Code result
P23A9
Communication Fault Forced Engine Shutdown
Moderate severity
What it means
A safety-critical communication loss between control modules has triggered a forced engine shutdown. The ECU could not validate signals it needs to operate safely (e.g. throttle commands, brake state) and stopped the engine.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Bus communication lost
highOne of the most commonly reported causes for this code — check this first.
Gateway module routing CAN messages incorrectly
lowLess common, but worth ruling out after the more likely causes.
CAN terminating resistor (120 Ω) drifted out of spec
lowLess common, but worth ruling out after the more likely causes.
Related help
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