I moved a working 3.5 L engine and transmission from a 2013 Nissan Maxima to a 2012 Nissan Maxima. All of the electrical connectors hooked up OK but it will not start and it has several codes. Someone told me I may have to move the wire and harness because they are years specific. Does anyone know if that’s correct?
davidaan
Post the exact DTC codes as read from a portable scan tool such as Uxxxx or Pxxxx here on the forum. With the loss of the communications with ECU, TCM, intelligent key error, also the security light flashes and lost communication with CVT, it's very likely the CAN (Controller Area Network) serial communication lines for real time application has failed. They are on-vehicle multiplex communication lines with high data communication speed. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation. In CAN communication, control units are connected with 2 communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring. Inspect those lines for possible breaks.
You can download a copy of the FSM from this web site:https://ownersmanuals2.com/. The section EC.PDF is the one you need to read. The most common problem with no-start Nissans is a bad brake switch. If that's malfunctioning, you'll get normal lights on the dash when you press the button, but no cranking. A second press will simply cycle to "off". If the problem is the battery or connections, the car will try to crank but you'll get clicks and blinky lights instead of the starter spinning. If so, check all your ground and power connections, particularly the 12mm nuts that attach the battery lugs to the cables. Those are known to work loose and cause all sorts of intermittent issues.
At this point you'll have to determine if there's an ignition or fuel delivery problem:
* Testing fuel delivery:
You can Tee-in a temporary fuel pressure gauge between the fuel feed hose and the fuel rail; now turn the ignition key to the run position but DO NOT TRY TO START THE ENGINE. The fuel pressure reading should be around 51 psi which would be a static reading. You can also spray some engine starting fluid or carb cleaner into the intake to see if it starts up momentarily; if it does, then you know it's a fuel related problem.
The fuel injectors may not be firing. This can be tested with a "noid" light probe for each injector harness connector.
* Testing ignition:
Pull a coil pack to test; use a spare spark plug in the coil pack to test; ground the plug base with a jumper wire to the engine block; see if you're getting a spark while trying to start the engine.
* There may be a major intake system vacuum leak:
Check the intake manifold nuts to make sure they are tight. The gasket may have failed. Also check the intake plenum bellows at the throttle valve and at the MAF for cracks or loose clamps.
You can download a copy of the FSM from this web site:https://ownersmanuals2.com/. The section EC.PDF is the one you need to read. The most common problem with no-start Nissans is a bad brake switch. If that's malfunctioning, you'll get normal lights on the dash when you press the button, but no cranking. A second press will simply cycle to "off". If the problem is the battery or connections, the car will try to crank but you'll get clicks and blinky lights instead of the starter spinning. If so, check all your ground and power connections, particularly the 12mm nuts that attach the battery lugs to the cables. Those are known to work loose and cause all sorts of intermittent issues.
At this point you'll have to determine if there's an ignition or fuel delivery problem:
* Testing fuel delivery:
You can Tee-in a temporary fuel pressure gauge between the fuel feed hose and the fuel rail; now turn the ignition key to the run position but DO NOT TRY TO START THE ENGINE. The fuel pressure reading should be around 51 psi which would be a static reading. You can also spray some engine starting fluid or carb cleaner into the intake to see if it starts up momentarily; if it does, then you know it's a fuel related problem.
The fuel injectors may not be firing. This can be tested with a "noid" light probe for each injector harness connector.
* Testing ignition:
Pull a coil pack to test; use a spare spark plug in the coil pack to test; ground the plug base with a jumper wire to the engine block; see if you're getting a spark while trying to start the engine.
* There may be a major intake system vacuum leak:
Check the intake manifold nuts to make sure they are tight. The gasket may have failed. Also check the intake plenum bellows at the throttle valve and at the MAF for cracks or loose clamps.
Rogoman, I was told by a mechanic from just answer that I am going to have to use the wiring harness from the car that the engine came from because the harness’s are year specific. All of the electrical connectors matched up and plugged in.. That made me think the two were comparable with each other but I haven’t been able to get the start button to engage the starter yet. Do you know if I am going to have to change the wiring harness?
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