Randomly will not start

2009 FORD FLEX
145,000 MILES • V6 • 2WD • AUTOMATIC
Avatar
TOMGARCIA38
  • MEMBER
  • 3 POSTS
Bought this vehicle used that randomly won't start. The dash lights up, music and navigation work, lights work. Engine won't even make a noise like it's trying. Eventually we'll come back like 30 minutes later and it will start up just fine. What is frustrating is that no mechanic will/can diagnose it without it actually happening in front of them and of course the car won't misbehave when we actually want it to.

So far we have replaced; battery, had a locksmith reprogram the keys, checked fuses, replaced ignition switch, removed an aftermarket alarm system. While at AutoZone they said the computer shows no signs of anything being wrong with the starter, alternator or battery.

About to sell and buy another car. Can anyone help?
Jan 26, 2020 at 4:31 PM
Advertisement
Avatar
BMDOUBLE
  • CERTIFIED EXPERT
  • 1,139 POSTS
Intermittent issues with the vehicle's communication network are common on these vehicles and always will leave a code in the power-train control module, but 9 out of 10 technicians cannot properly diagnose this sadly. If you can have the codes retrieved after you have another no start symptom there should be some codes stored in the PCM or SJB, we can help decipher and narrow down the cause.
Jan 26, 2020 at 4:54 PM
Avatar
TOMGARCIA38
  • MEMBER
  • 3 POSTS
So if I'm understanding correctly, whenever this is happening a code is stored in the PCM and after the car starts, I can have these codes retrieved to hopefully narrow down what's going on? Can you recommend a way to have these codes retrieved? Thanks for your time and assistance.
Jan 26, 2020 at 5:03 PM
Advertisement
Avatar
BMDOUBLE
  • CERTIFIED EXPERT
  • 1,139 POSTS
Yes, even a low voltage issue will set codes in several modules. Your local parts stores usually will retrieve codes from your pcm for free and either get you a printout or just write them down. They may or may not be able to get codes from any other module though.
Jan 26, 2020 at 5:35 PM
Avatar
TOMGARCIA38
  • MEMBER
  • 3 POSTS
Update: Took to Autozone and they were unable to find any codes stored even though the car wouldn't start earlier.
Jan 26, 2020 at 7:07 PM
Avatar
STEVE W.
  • CERTIFIED EXPERT
  • 15,116 POSTS
Depending on the store they may only scan for the common OBD II codes not all of the codes available like from the security modules or other controllers. However random starting like that sounds like a corroded connection in the starting system. It is providing power to the lights and the rest but the starter isn't getting voltage. When it doesn't start, if you have the lights and the rest on, do they do anything like dim or shut off when you attempt to start it? Does their seem to be anything in common with the times it won't start, like just came off a long drive? Outside temperature dropped? Hit a bump?
Have you tried shifting into neutral or shifting into a gear and back to park?
I would also check the starter relay and it's connections in the battery junction box under the hood. I have seen those corrode and cause random issues.
Image (Click to enlarge)
Attached Media
Jan 28, 2020 at 10:55 AM
Avatar
BMDOUBLE
  • CERTIFIED EXPERT
  • 1,139 POSTS
Yeah most parts stores only have very basic scan tools that do not have the capability to read codes from body modules, and this will need to be dealt with at either a dealer or a good independent shop.
Jan 29, 2020 at 12:44 PM