P0085
Exhaust Valve Control Circuit Low (Bank 2)
Powertrain Emission Controls Variable Valve Timing 🟡 Moderate — Fix within a week
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What This Actually Means
In plain language — no jargon

The engine's computer detected that the exhaust valve control circuit on Bank 2 (the side without cylinder #1) has abnormally low electrical voltage. Think of it like a dimmer switch stuck too low—the valve isn't getting enough power to open and close properly.

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Symptoms You May Notice
3 known symptoms for this code
Check Engine Light illuminated
Rough idle or engine hesitation during acceleration
Reduced fuel economy and possible loss of power
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECM monitors the control voltage signal sent to the exhaust valve solenoid on Bank 2, expecting a normal range during operation. When the circuit voltage drops below the minimum threshold, the ECU logs this fault because the solenoid cannot reliably actuate the valve. This prevents proper exhaust valve timing and cam phasing.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Exhaust Valve Control Voltage 10-14 volts (engine running) Below 5 volts or open circuit
Solenoid Coil Resistance 6-12 ohms Open or shorted (>100 ohms or <1 ohm)
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Battery and connections
Clean corrosion from battery terminals and check ground connections to engine block.
2
Wiring harness and connectors
Inspect wiring to the exhaust valve solenoid Bank 2 for breaks, corrosion, or loose connectors.
3
Exhaust valve solenoid Bank 2
Test solenoid resistance with a multimeter; replace if open or shorted.