Code result
U0421
Invalid Data Received from Throttle/Pedal Position Sensor
High severity
What it means
The ECU receives implausible accelerator pedal or throttle data over the bus. The engine drops to limp-mode with reduced power.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
Pedal sensor partially failed
mediumA plausible cause — test and verify before replacing parts.
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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