Hello, I wanted to know if there is a way to test for a faulty engine control module/computer, I have a 2006 ford ranger that has a wierd hesitation problem I have been unable to solve, Posted earlier, Today on a hunch I reset the computer by disconnecting the battery, When I reconnected the check engine light went off, as expected, I ran the car and it ran great, I drove ~10 miles with no issues. I stopped the car and turned it off, When I started it back up all my symptoms returned!, So I disconnected the battery again and it immediately rode great, Turned the car off and low and behold right back to the problem, Is there a way to run a diagnostic or test on the control module?
I think that this is very unlikely to be an ECM problem. When you replaced the fuel pump, did you measure the pressure with the new pump? If it is still low, then maybe the problem was the fuel pressure sensor? (I think that 2006 was a returnless system that uses a fuel pressure sensor and electronically regulates fuel pressure. If not, then there will be a fuel pressure regulator and a return line.)
Are you still getting the same check engine codes?
It would be much less confusing to those trying to help if you would’ve kept this all in one thread!
Thanks for the reply, I did check fuel pressure and it is the same, I found out fuel pressure is supposed to be 60-65 PSI, so there was never an issue, OH Well, I also checked fuel flow to make sure I did not have a clog or a pinched fuel line. On the last reset the problem has not reoccurred so I have not checked the codes, I went to a ford dealer to ask if they could check the module, apparently they can but did not have an open slot till later in the week, The fuel pressure sensor might make sense, you are correct that it does not have a regulator. Maybe the reset computer is running richer by default? I will have a somewhat extended drive tomorrow so I will see if the problem re-occurs, I am sure it will.
A Wal-Mart code reader costs about $100 and is easy to operate. Innova is the brand name. It will cost the same to have the dealer check the PCM and suggest a repair procedure.
Connect the tester and that is the way to check the PCM.
A possibility – It’s not a faulty ECM, but it is a computer related problem. What I’m thinking is that there is a real – non-computer – problem that the computer is detecting
ECMs often don’t set a code and turn on the Check Engine light until the second time they see a problem. So, the first time around, the ECM sees a problem, makes a note of it and runs the car open loop without trying to adjust fuel flow, timing, mixture, etc to maximize performance and minimize pollution. Car runs fine although it is probably getting mediocre mileage and may be emitting more pollutants than it should.
Second time around, the ECM sees the same problem, turns on the Check Engine Light and tries to work around the problem. That doesn’t work quite as well and you notice performance problems.
You probably need to check what code accompanies the Check Engine Light. Hopefully, it will point you either to a faulty sensor or to a condition that causes something not to work quite right.
Thanks, I think I agree with your assesment,
Past codes seen: Codes found P0171, P0300, P0303, P0304, PO305, P0316
Almost everything points to a vacuum leak or a bad component, I have replaced the idler air control, cleaned the MAF checked all the vac hoses. One thing I am unclear is EGR? I cannot seem to lacte one although there are references to it on the web(Parts). There is nothing coming directly off the exhaust manifold to the intake system that I can see, Another thought was a problem with the catalytic converter losing air flow as it heat up and cools down, however I am not sure why I would get a lien code if this is the case?
Automotive electronic parts are the biggest rip-off there is…You can buy a new laptop computer for $400-$500, with a screen, keyboard, 2 drives, 4 USB ports, Wi-Fi…But a naked motherboard for your car costs $1200??? Give me a break…This is a $100 part…But when they have you by the short hairs…