C0900

Device Voltage Malfunction

Severity

⚠️ Medium

Can you drive?

Do not drive — repair immediately

Approx. repair cost

$22–111 (est.)

Symptoms

Incorrect operation of electronic systems
Check engine light comes on
Reduced engine efficiency
Problems starting the engine

Causes

Device power supply fault
Battery or alternator problems
Wiring harness damage
Electronic module malfunction
Short circuit or open circuit

How to Fix

Check battery and generator voltage
Inspect the wiring harness for damage
Check the integrity of the device power supply circuit
Replace the faulty module or sensor
Firmware or ECU calibration if necessary

Related codes

P0562 P0563 B2100 B2101