What does fault code P0085 mean?
Fault code P0085, applicable to all vehicle manufacturers, means “Exhaust Valve Control Solenoid Circuit Low (Bank 2).”
Background Knowledge: The camshaft’s function is to control the opening and closing of the valves. In a variable valve timing system, the electronic camshaft adjustment valve (or oil control valve, OCV) adjusts the camshaft angle by changing the oil pressure to the camshaft adjuster (mechanical) based on instructions from the Engine Control Module (ECM), ensuring the valves open and close at the optimal time. This fault code appears if the exhaust camshaft adjustment valve circuit voltage falls below the calibrated minimum value.
Symptoms of Fault Code P0085
The main signs of a P0085 error are:
- Malfunction Indicator Lamp (Check Engine Light) illuminated
- Rough engine operation
- Power loss
- Increased fuel consumption
- Difficulty starting the engine
- Vibration at idle
Main Causes of Fault Code P0085
- Faulty Valve Timing Control (VVT) solenoid
- Damage to electrical wiring or connectors
- Contaminated engine oil
- ECU (Engine Control Unit) failure
- Overheating or solenoid wear
Fault Code P0085 in Common Vehicles
- P0085 in Ford Focus: In these vehicles, the P0085 error is often due to wear of the phase shift solenoid, especially after traveling approximately 100,000 km.
- P0085 in Subaru Forester: It can manifest due to contaminated engine oil, particularly with infrequent changes. Often accompanied by reduced oil pressure.
- P0085 in Nissan Altima: Typically caused by a failed VVT solenoid or an open circuit. Requires a detailed inspection of the circuit.
- P0085 in Toyota Camry: The error can be caused by expired engine oil and a clogged oil filter. Can be addressed through regular maintenance.
- P0085 in Audi A4: It is related to the variable valve timing system. Diagnosis should be comprehensive, using a proprietary scanner.
How to Diagnose Fault Code P0085?
- Connect a diagnostic scanner and read the fault code.
- Clear the fault code and check if it reappears.
- Inspect wiring, harnesses, and solenoid connectors for integrity.
- Measure solenoid resistance—should be between 6-12 ohms (depending on model).
- Assess the condition of the engine oil and oil filter.
Possible Causes and Diagnostic Methods
Possible Cause | How to Check? |
|---|---|
Defective VVT solenoid | Check resistance, replace if necessary |
Open or short circuit in wiring | Visual inspection and diagnosis with a multimeter |
Contaminated oil or filter | Check and replace oil and filter |
ECU failure | Diagnose with a dealer scanner |
Tools Required: OBD2 scanner, multimeter, set of wrenches and screwdrivers, contact cleaner, vehicle service documentation
How to Fix Fault Code P0085? (Problem Solutions)
Simple Repair Methods
- Reset the fault code and see if it reappears.
- Inspect and clean connections and connectors.
- Replace engine oil and filter.
In-Depth Diagnosis and Repair Plan
- Replace the VVT solenoid if it is faulty.
- Repair or replace wiring.
- Replace or reprogram the ECU.
Troubleshooting by Symptoms
Symptom | Possible Solutions |
|---|---|
Engine misfire | Inspect and replace the solenoid |
Increased fuel consumption | Clean or replace the VVT solenoid |
Check Engine light on | Perform comprehensive diagnosis and reset fault |
P0085 FAQ
What to do if I encounter fault code P0085?
Fault code P0085 indicates a deviation in the timing solenoid circuit. The cause can be as simple as contaminated oil or an electrical fault.
Is it possible to drive with a P0085 error?
No, driving with this fault can lead to reduced power, engine overheating, and damage to the timing system.
Will fault P0085 reset after an oil change?
Sometimes, if the problem was caused by oil contamination. However, for reliability, it is recommended to reset it with a scanner and check if the error returns.
Can I fix P0085 myself?
Yes, if you have experience and tools. For example, you can change the oil, clean contacts, or even replace the VVT solenoid. However, for accurate diagnosis, it’s best to consult a specialist.
Does fault P0085 indicate a problem with engine bank 1?
It refers to Bank 2, which is the cylinder bank that does not contain cylinder number 1.
Do I need to replace the VVT solenoid for a P0085 error?
Yes, if diagnostics confirm it is faulty. However, it is advised to first check the condition of the oil, filter, and wiring.
P0085 Related OBD2 Faults
- P0014 – Timing Over-Advanced (Bank 1)
- P0024 – Timing Over-Advanced (Bank 2)
- P0080 – Exhaust Control Valve Circuit (Bank 1) Signal High
Important! If the P0085 fault is not corrected promptly, it can lead to more serious engine problems, including damage to the valvetrain or catalytic converter. Regular engine maintenance, including timely oil and filter changes, can significantly reduce the risk of such errors. If the error appears, do not ignore it; diagnose it as soon as possible.