Wait, There’s More!
On to a 2007 Ford F350 6.0L diesel with a P0401 (EGR Insufficient Flow) DTC detected. I encountered this problem vehicle as I was teaching a class. The shop I was at had installed a new EGR valve that did not resolve the problem. You can go to MotorAge.com/egrvalve to see the EGR valve operating by scan tool bi-directional control on the TST YouTube channel. The problem with this EGR system as well as many others is that the EGR passages clog up and need to be cleaned. I recommended that they contact their local BG representative and purchase the special EGR cleaning kit along with the chemical. Once they ran the BG cleaner through the system the problem was solved. This is a great service that needs to be performed on diesels as well as gas engines such as Honda motors that are known to clog EGR passages.
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A lack of routine oil changes brought a 2005 Subaru Legacy 3.0L 75K into the shop. It came in with a P0011 (Intake Camshaft Position Timing Over Advanced Bank 1) and P0021 (Intake Camshaft Position Timing Over Advanced Bank 2) along with an idle and stalling problem. This engine had clogged VANOS (Figure 8) screens that are inserted in the solenoid’s oil passages. The problem most likely would have not occurred if the regular maintenance along with the correct oil was used during regular oil changes.
The 5w30 oil required for this engine is an ILSAC (International Lubricant Standardization and Approval Committee), GF-3 with an API SJ standard. The use of the wrong oil, low or dirty oil can cause the above DTCs. To test the system, use your scan tool’s bi-direction ability to actuate the valves. An alternative procedure also can be used by connecting a Power Probe or fused jumper wires. The caution is to make sure you index the terminal to make sure what side has power and ground in case the solenoid uses a diode. Turn the key off followed by disconnecting the wires to the solenoid, followed by turning the key back on and touching the Power Probe point very carefully without jamming it in the terminals to see what side has power and ground. Your next step would be to apply power and ground to the solenoid to see if the engine makes an RPM adjustment as the phaser adjusts one way or another.
Our last story of the day is a 2006 Chrysler 300C 5.7L with a NAG1 transmission and a complaint of a vehicle that will not move until the engine is shut off and restarted. This vehicle is one that I owned and at the time was under warranty. I noticed that the transmission developed a leak and returned it to the dealer. They installed a new connector plug and wiring harness that is usually a problem but was not in this case. The vehicle was returned to me and still leaked transmission fluid that I found was leaking from the front pump seal.
I returned the vehicle to the dealer where they replaced the front seal and now that all the leaks where fixed I thought the problem would be solved. Anytime the vehicle was driven for more than three hours, the vehicle exhibited the same problem it had before. I would be driving anywhere from 5 mph to 75 mph and suddenly experience no forward speed until I coasted the car over to the shoulder of the road, placed the selected in park, followed by shutting it off and restarting it. The final fix for this vehicle was a complete transmission replacement. The moral of this story is to make sure a transmission leak gets repaired as soon as possible as not to cause a low fluid level that will overheat the electronics in the transmission. It seemed that the leak went on way too long, causing an internal problem that put the unit in limp mode.
As professionals, we see cases just like the ones I shared here today every day in our shops. We share these stories with our customers in every effort to help them save money in the long run. Why, then, do so many customers refuse to perform routine maintenance? No matter, I guess. I’ll fix it either way!
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