My daughter just turned 16 in April. Her dad gave her his old 2014 Camry but had to swap the motor out as he blew the original one and it has just been sitting for a good 2 years now. Anyways, His mechanic took care of finding and swapping the motor (only has 75,000 miles on it) but it was still having issues after the swap.

We have the car now and my husband has been trying to figure out what to do about the few issues its having. The issues are the dash shows the car in drive all of the time, it never changes to P, R or N, backup camera stopped working, slow transmission shift from reverse to drive, steering is tight but not as if there is no power steering just tight. After doing some research my husband has determined that the motor is from a 2017 manual Camry and swapped into the 2014 automatic. And it All boils down to the wiring harness and ECM/ECU. I’m not sure what exactly I’m asking other than:

has anyone encountered this and been successful in this type of engine swap?

Is it even possible to get to running smoothly and in harmony?

Should and could we continue on driving it with issues above?

Dad told stepdad he’s going to look for another motor from an automatic transmission Camry but in the meantime, any suggestions, advice, or personal experiences would be helpful!

and forgive me if I make zero sense, I’m just a mom who knows squat about auto mechanics! I can try to clarify anything if needed. Thanks!

 

The 2014 and 2017 are the same generation which means no major changes.

There may be minor changes between an engine connected to an auto trans and manual trans. Typically, in this case, parts would be swapped from the bad automatic trans connected engine to the good manual trans connected engine. Its standard procedure because the same engine model could have minor changes between years being swapped.

Other than the issues posted does the engine run OK?

No check engine light on?

What does smoothly and harmony mean?

On the auto transmission, basic trans gear selection as in Park, Reverse, Forward, N, 1, 2 is selected by rotating a shaft that comes out of the trans housing. This shaft has a lever arm connected to it. The cars gear selection shifter inside the car is connected to a push/pull cable which connects to this lever. When the arm moves the lever moves, and with this rotates the shaft coming out of the trans. You can see movement action when looking down at the trans with the hood open and having someone move the shift arm.

There is multi position rotating electrical switch installed on the trans shaft behind the lever. When the shaft rotates the switch changes electrical contacts. The cars dash gear indicator lights are connected to this switch. The switch is also connected to the cars ECU.

The trans gear selection is controlled manually and electrically. Manually as in moving the shift arm. The rotating arm physically changes the hydraulic valving in the trans. Electrically, as in the rotating switch tells the computer what gear has been selected as in P, N, R, 1, 2.

If the dashboard gear indicator light never changes from Park but the car is able to go forward, back, etc. then something may be wrong with the rotating switch or wiring to it. Since the computer "thinks" the trans is in Park but the gear shifter is in say Drive, this may cause issues of trans shifting gears when driving.

Check out the switch before considering looking for another engine.

You should be able to swap a manual engine to an automatic trans. You may need to swap a few parts on the engine such as in sensors, but this depends on if the manual and auto trans engine has differences.

If YOUR car is an automatic, then it has the right ECU and wiring harness for an automatic. The manual trans donor car would have an ECU and harness for a manual trans which means NO wiring for the rotating switch.

Your mechanic should have dealt with this issue when swapping engines.
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So, the “non-mechanic husband” here. It had check engine light, trac control light, ABS, and the red steering wheel light on occasion. The display says “D” until you get it in manual mode and then it registers the gears right. But park, neutral, Rev never come up. The engine ran fine but it would cause it to go into limp mode and cause the electric steering to go out (harder than usual to turn). The code that came up was P0705 so I replaced the TRS with the exact one that I took off, same pin out and all. Still the same. I noticed the plug end clip broke on the harness so I replaced it with a 9-pin LAZIP harness that is supposed to be for that exact car. Wired it like the old one was wired. Still the same. Few days later I went to hook up the OBD and it started for 10 or so secs and died. Hadn’t started since. I got the wiring diagram and went pen for pen from the ECM plug to the TRS plug and matched the pin out on the TRS. I’m pretty sure I got it aligned correctly, but when I put it still shows D on the display and showing the back up camera and back up lights coming on when it is in neutral. I tried to switch the wires and the backup cameras and light came on when in park. There’s also a jumper wire (with an in line fuse) in the fuse box going from a green wire to a purple wire. I took it off cause I know that’s not right, but I can’t figure out the logic that ecm wants. My brain is tired. Any help would be life saving more than likely.

 

The trouble code is for the gear shift switch. Perhaps the switch is bad. Owners have found ways to open then up, inspect and clean them. If you have an ohm meter check, unplug the switch and check if it works OK as doesn't stay at the Park position.

The cars computer programming can have a number of dash indicator lights come on when systems related to the indictor light system are OK. If CEL is on, by programming the computer may turn off the TRAC and ABS lights depending on code. If the engine goes into limp home mode, then it will do the same thing. There may be nothing wrong with the ABS and TRAC systems.

I suspect limp home and all the icon lights coming on are related to the switch as indicated by the trouble code. These switches do fail.

 

I’ve replaced the park/neutral switch with the same one it had when it arrived from the mechanic. I’ve checked logics, wired it exactly how the ECM is expecting it. Verified by matching it pin for pin. Today I’ve learned that I’ve got a short somewhere, and/or the mechanic spliced into a wrong wire? The green wire, which has continuity with pin 67 in the ECM, the one designated for drive, is getting 12v at all times. The common can’t be a signal wire. With the TRS plugged in, the ECM unplugged, battery connected, and key on, the starter relay buzzed. I unhooked the TRS and tried again and it still buzzed. Which means, I think, that there is a short or wrong splice in the system. Or, it could be the jumper wire that the almighty mechanic jumped from the starter wire to the BCKUP LP wire that feeds power to the TRS, has created a back feed into the TRS matrix and caused a **** show. Over loading a 7.5 fuse that looked like hell but still had continuity somehow. I also learned that the engine harness that I thought was the original 2014 is in fact the 2017 harness. Which throws a **** wrench in the whole fiasco. I don’t know whatelse to do except wire it up like the ECM expects it. I’ve mended the wire that where cut from the jumper install, and also mended another purple wire that was brilliantly wire nutted together in the fuse box as well. As of now, it turns over but won’t run. Like the fuel is cut off for some reason. Display says D still because the TRS doesn’t have power getting to it. This whole thing is way over my head but I don’t really have many options. The bill for a mechanic that charges $100+ an hour to figure out and fix this nightmare is way above my dream budget, much less my real budget. Any help on this would be greatly appreciated and life saving.

 

The info has the 2014 and 2017 in the same generation car (Gen 7) with a facelift in 2015. A facelift is mainly cosmetic changes but there could be minor electrical changes.

Do you have the wiring diagrams for both 2014 and 2017 years? Get the wiring diagrams and compare.

Toyota has a website where for $25 one can get 2 day access or for $95 a month access to all manual, etc. and download what you want.

TIS

Did the trans indicator lights work normally and the car drive normal prior to this engine swap?

Just what all what did the mechanic do when they swapped engines? You state they swapped the wiring harness, if so then why?

The trans model should have remained the same between years and as such a bolt on task including the trans indicator switch.

The cars wiring should have something called a circuit opening relay or such. This relay turns on the fuel pump when the engine is cranking over to start and when the engine running. Try powering the fuel pump directly.

Unless something is new, the trans rotary switch gets 12V power from a fuse sends perhaps the Gauge fuse. The switch then sends power to ECU terminals as determined by the switch position. The ECU then sends a signal to another electrical module with turns on the gear indicator light. The P wire goes from the switch goes directly to the ECU and has no other wiring connected it this wiring. If the P light is always on when say the P wire is disconnected at the switch, then the "P" ECU terminal may be getting powered elsewhere.

Toyota can make minor electrical changes within the same generation. As you say, maybe the 2014 ECU is looking for 2014 electrical inputs from a 2014 wiring harness connected to 2014 components.

A question is why the later model year harness swap?