P0013: OBD-II code P0013 flags an open or shorted circuit at the bank 1 exhaust camshaft VVT actuator solenoid — the PCM can't control exhaust cam timing.

Symptoms

• Check engine light is on; engine may hesitate under load and idle roughly at cold start.
• Reduced power at low RPM and slightly worse fuel economy because exhaust valve timing is stuck.
• Emissions rise because internal EGR (from exhaust cam phasing) can't be modulated correctly.

Common causes

• A failed exhaust camshaft oil control solenoid on bank 1 with an open or shorted internal coil.
• Damaged wiring or a corroded connector at the solenoid, common in the valve cover area.
• A failed PCM VVT driver — less common but possible after electrical events.

What to do?

Measure the solenoid coil resistance with a DMM (typically 7-15 Ω). Check for power and ground at the connector when the PCM commands it. Replace the solenoid if the coil is out of spec. Change engine oil to OEM viscosity — sludged oil is a chronic root cause of VVT solenoid failure.