Meaning

The ECM detects a generic fault in the injector drive circuit. P0200 signals a problem in the common injector control bus before the specific cylinder can be isolated. The ECM cannot detect a consistent response from the injector circuit.

Common causes

• Open in the common injector circuit wiring
• Short circuit in the common injector control bus
• Disconnected or corroded injector wiring connector
• Open fuse or protection in the injector supply circuit
• ECM injector output driver failure

Symptoms

• Check-engine light on
• No-start or very hard start
• Misfires on multiple cylinders
• Smoke and irregular emissions
• Limp-home mode active

Severity

What to do

1. Check supply voltage and ground at the common injector circuit connector
2. Measure each injector resistance and compare against specification
3. Inspect the common injector wiring for breaks, shorts, or corrosion
4. Check the injector circuit protection fuse
5. Examine the ECM output driver if all external checks pass

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