Toyota Repair Problems? Ask a Mechanic for Answers ASAP
Do you have any wiring diagram, voltmeter and a reasonable knowledge of how to use it? Or the parts that you replaced all new parts or where the used? Was there anything done Recently leading up to this current problem that might help me understand what's going on?
Let me look at the wiring diagram when I get into my office I will get some test together for you to check. Probably won't be till early afternoon.
The first thing I need You to do is confirm that you have 12 V to the 10 amp ECU-B fuse and the 20 amp DRL/LCK fuse in the fuse box under the hood? Next I need you to locate the back door ECU which you've already replace there are two connectors in connector A pin number five is a white wire with a red tracer is there 12 V to this wire? This would be with the key off and out of the ignition. The pins are identified by removing the connector with the lock tab at the 12 o'clock position and the face of the connector looking at you pin number one is the top left and the pins are counted up in sequence to the right then the next row. Let me know if these two fuses are blown and if you have 12 V and to the white wire with a red tracer at the body ECU.
Just to clarify you're getting no voltage to that 20 amp door lock fuse and you're 100% certain you are on the correct fuse? If you remove the fuse do either of the female pins in the junction block/fuse block have 12 volts?
This is a very complicated situation. If you have 12 V at the 10 amp ECU fuse and you are on the correct fuse yet have no power to the door control ECU in the back door there is either a malfunction in the body ECU pin connections or a problem in the wiring. That is the power supply that feeds the body ECU And the back door ECU when the key is in the off position. Not having 12 V to the 20 amp doorlock fuse even the female pins in the box indicates a problem within the box. That power supply comes directly from the battery into the bottom and into a busbar that feeds multiple fuses in that box. It would be extremely unlikely to see a problem inside the box a less corrosion or water got in there because they were four wheeling. I'm going to submit an offer for a premium service which allows us direct contact via telephone. This comes as an additional cost but may be easier to get this resolved versus trying to go back and forth with my schedule and your schedule. I'm about finished for the evening myself. You can accept this offer at any time if you would like. Having the freedom to discuss this over the phone and exchange information via email will probably be quicker.
Click this link and download the illustration. It will time out. Do any of these fuses in that same block have power to them?
Click this link and this link and save the illustrations. They will time out. Locate the connector as seen highlighted in yellow. This is just inside the left quarter panel where the harness comes through the boot from the door. Locate pin number 10 disconnect the connector is or any corrosion that connector. Locate pin number 10 does the white wire with the red tracer Which is the same wire that goes to the back door ECU that has no power. Is there any corrosion in this connector and does the white wire with a red tracer at pin number 10 have 12 V to it? I will be available most evenings especially tomorrow and Friday I have not much planned and would be available to walk through things on and off during the course of the evening. I am on East Coast time.
Have a good evening. Remember that my information is only as good as your ability to follow the steps and test everything appropriately. Doesn't take a rocket scientist just make sure you have good grounds on the black lead of your voltmeter and your probing and checking the right pins and voltages as I am asking. Otherwise we will end up on wild goose chases and get nothing accomplished.
There has to be something going on in that harness going up to the back door ECU. That white wire with a red tracer is the constant 12 V power supply that makes the back door ECU work on the system. There are multiple things you have to take place but the power supply is the most important. That explains why it only seems to want to work with the key in the on position. That system has to be active continuously that's why they power supply comes directly from the battery through those two fuses I listed then powers of the body ECU and the back door ECU. Let me know how things go.
If that pin pulled out of the connector it's possible there is damage to that connector and by disconnecting it you may have aggravated something else look very carefully at those pins in the connector make sure there's no corrosion then I would probably pull the harness out of the door and strip it down and inspect it. There had to be reason why the wire was pulled out for the wire was damaged. Getting 12 V to the back door ECU is critical but there are other multiple things that have to be in place for the system to work. This includes getting to the body ECU and checking things further.
You are welcome.