My 2005 Honda Accord with OBD codes: 0507 and 0011. Howto Troubleshoot

Question

The check engine light came on very recently with two error codes being thrown. From this source, the following will cause 0507

P0507 HONDA - Idle Control System RPM Higher Than Expected

• A vacuum leak
• Leaking air intake after the throttle body
• EGR valve leaking vacuum
• A faulty positive crankcase ventilation (PCV) valve
• Damaged/failed/dirty throttle body
• Failed EVAP system
• Failed IAC (idle air controller) or faulty IAC circuit

This source says the following will cause 0011

P0011 HONDA - Variable Control Timing System Malfunction

• Dirty Oil
• Low engine oil level
• Valve Timing Control (VTC) open or shorted circuit.
• Valve Timing Control (VTC) electrical connector
• Faulty Valve Timing Control (VTC)
• Damaged ECM

What can I do to further identify the source of the problem?

Answer 1

The two faults may or may not be related

For the idle speed code:

1) Clean the throttle valve.

2) Relearn the idle speed. To do this remove both battery cables and connect them together for 10 minutes. While they are apart take the opportunity to clean off any the acid. After 10 minutes connect them back together, start then engine and let it run at idle for at least time minutes with no loads such as lights or A/C. Clear the fault codes, drive the car to see if it returns. This idle speed should stay near 700 rpm when then the engine is warmed up.

3) If this does not work have it checked to see if Honda TSB # 06-040 applies. This TSB suggests a computer software update may be needed for this problem.

For the P0011 code:

Check the engine oil; if dirty change it, if just low fill it. Low engine oil can cuase this code. Repair any oil leaks. Note a poor oil change history could cause timing chain wear which can also cause this code. The idle control problem above can cause this code so as long as the oil level is good fix the idle problem first.