The complete symptom is a cold-start misfire or a rough idle concern. Now, a misfire or rough idle isn’t that uncommon in the grand scheme of things, but in this case it’s what’s causing them that’s unusual.
A simple solution for a common trouble code.
An ASE-certified technician walks listeners through a diagnostic dilemma with 11 trouble codes, an intermittent problem and a dashboard lit up like a Christmas tree on a 2001 Blazer.
The vehicle was a 2013 Volkswagen Jetta with a 2L TDI engine. Sometimes it ran great, but sometimes it would idle high and when you would press on the accelerator, nothing would happen. This was a perfect diagnostic dilemma for industry experts.
A customer brought in a 2007 Subaru Legacy with the 2.5L 4-cylinder EJ25 engine. The owner complained of an engine vibration. From the initial description, it sounded like a pretty typical misfire issue.
Similar to our last podcast, today we’re taking a slightly different approach and discussing a specific vehicle that was brought into the shop of one of TechShop’s contributors, Olle Gladso.
Sharing the diagnostic approach of industry experts from our Maximizing Tools column, today's Code Reader looks at a 2003 Mitsubishi Eclipse with the 4G64 2.4 liter and a complaint of a rough running condition and a no-start when warm. A DTC scan revealed DTC P0340.
This code monitors the oxygen sensor voltage and when it sets, it means that the PCM sees that it has remained low for over a predetermined amount of time, usually 2-4 minutes, but that varies depending on manufacturer.
TechShop discusses the relationship between clearing DTCs and readiness monitors.
P0300 sets when the control unit recognizes that one or more of the cylinders is not contributing, or working as hard as the others.
