Hi guys Im having trouble with my vehicle its seems to be on limp mode and no scanner has been possible to read the computer to communicate back with codes would you guys have any idea what could be going on?
First you may want to determine if your data port has power and grounds to operate and communicate with a scanner.
Grab a multimeter and check pin 16 for battery voltage (12 volts+) and pins 4 and 5 for ground.
So switch the multimeter to 200K on the OHM scale.
Connect the black lead of the multimeter to a good ground and probe both Data Port pins 4 and 5 with the red lead..
You should be reading 0 on both pins
Now switch your multimeter to Volts DC and set it to the 20 volts scale.
Again, connect the black lead of the multimeter to a good ground and probe Data Port pin 16.
It should read battery voltage. Around 12 volts+
Now it should go without saying not to go poking around the other pins.
Just check these 3
Thank you I'll give it a try, if not I may have yo change the ecu
If you try the fixes listed above and get nowhere you can always try to find a used ECU in a junkyard to replace the old one
If he jumps straight to that and it’s a nats car which the majority were the car still won’t start unless he can get it somewhere to have it programmed. I would avoid this as a first step
What can your scanner communicate with if it is only ecm you cannot read but can see abs or others your problem is most likely an ecm or a concern on the ecm branch circuit
