Hey everybody, glad to have found this place! ...not so glad about the 8th gen situation. Car was pretty much totaled but I brought it back to life due to financial constraints and used car market/loan rate being super high. Any way, here is the situation now.

P0974 code (it will not reset, so probably an electrical issue). I bought the solenoid off ebay, do you think it could be the actual part? He is shipping me another one in case. Could it be pressure sensors? Shifts into drive, just doesn't upshift past 2nd? At 40mph its pretty much at 4000 rpm.


Before 1


Before 2


After 1


After 2


Codes

Airbags did not deploy.

 

The path forward for testing depends on how confident you are on doing electrical testing on your car to properly diagnose.

The code is for an electrical fault in the shift solenoid A circuit, so something is messed up with the current running to shift solenoid A. It could be the solenoid has an open circuit, the wiring, or possibly the PCM. I think there is a connector for all the solenoids on the transmission that you may want to disconnect and check for corroded/poor connections. I'd also follow that wire harness back to the cabin to see if the damage from the accident was near that wire harness and you could possibly be dealing with a damaged wire.

 

Thanks for the reply! So I should be getting a replacement solenoid to hopefully solve the issue. There seems to be only one connection to the solenoid A part and the wire seems to be fine. However I have not tested anything with a multimeter yet. I’m also not 100% what to exactly test. The original solenoid was cracked so I replaced it.

How would I know if the PCM is the issue? Would the car spit out a code? Also could a low power battery be causing any of this?


Original Solenoid A


Original Solenoid A closer

 

I recommend getting the shop manual for your car. You can purchase on from automanualsource.com for ~$22 and is worth the investment.

Since your PCM is detecting a codes for the circuit, I'd assume the PCM is ok until you rule out wiring and/or solenoid failure. The testing tree starts with using a scanner to see what the PCM is detecting. I'm not sure if your scanner has that capability. The procedure goes through wire testing involving checks at the PCM connector with the PCM unplugged, then working towards the solenoid as a first pass. The shop manual will give you wire colors and connectors for testing.

Without a scanner that can do bi-directional controls, you have to come up with a game plan to understand the circuit and figure out a DIY way to do testing.

A quick pass of the procedures should give you an idea of where to find the power wire at the PCM (looks like pin C6 blu/blk) to ground. Then at the 8-pin connector for the transmission which is a blue wire.

Hopefully the replacement part will solve the problem. If not, then you'll have to try the DIY way to identify the wiring problem. We can probably help with a plan.

 

Ok, thanks I will look into that. Haven't done much electrical work so it will all be new. Also, just saw that the amber parts on the new headlight do not work (saw it when I hit the unlock/lock on the key). Then I saw the tail lights don't work either. Changed the bulbs and Driver Side #27 fuse. Still nothing, Not sure if the license plate lights work either, tried to change the bulbs but were so tight I broke one in the socket. So have to clean that little mess up. Could any of these be related?

 

It could be related, but I would treat as a separate issue. The light bulbs are easier to diagnose. You need good power and good ground for a bulb to work. A test light can quickly narrow down if you are missing power or ground at the bulb socket. Once you determine what is missing, you can work back to narrow down the root cause.

You may find that a wire harness was pinched and other wires or a ground could be damaged causing the transmission electrical problem.

 

Do you think I can use this to test the wires for the lights issue? I don't have a multimeter so probably have to get one ASAP.

 

You can pick up a basic multimeter that is inexpensive. A 12V test light would be very helpful as the test light draws more current and can identify most problems. If all of the lights that are powered by the red wire are out, then I'd check the 10A fuse #27 to see if it is blown. Fuse 27 is the power source for all the lights.

There are some good youtube videos on how to quickly check fuses using a test light that will make quick work of this. You can check all of your fuses very quickly using this method.

 

Okay I'll grab one from HD. Without knowing about the red wires I changed the brake light/tail bulbs and Driver Side #27 fuse before. The fuse was blown, but I just used a 10A spare from the under hood cover. Maybe I will buy another 10A fuse and see since the spare is really old. But I do see a continuous circuit in there. The fuses can be put in any direction right?

 

A fuse can be put in any direction.

I'd say fuses rarely get old during use. They are a thin piece of metal designed to handle a certain current and melt/blow when that current is exceeded. They blow to protect the wiring downstream from getting too hot and melting. If the replacement fuse is also blown, you definitely have a short in the wire harness to ground. You can try a new fuse, and I suspect the new fuse will blow immediately.

All the non-working bulbs you mentioned look to be on the red wire based on your description and the wiring diagram. You can verify by looking at each electrical connector of a non-working bulb. I would say the bulbs are likely good and don't need replaced.

I suspect the wiring harness got damaged in the area of the driver's fender where the vehicle got crushed, where the red wire (and maybe some others) is now touching some bare metal or a ground wire inside the harness. I suspect the front left lights coming off pin F10 is the short and causing the fuse to blow. You can use a test light to verify. Unplug the two bulbs on the driver's side that have the red wire. You'd have to unplug the F-connector from the driver's side fuse box. Find pin 10 on the F connector and verify it is a red wire. You would connect the test light to a 12V source and use the tip of the test light on F10. You have a short if the bulb lights up. You need the bulb of the test light in the circuit to create resistance and not cause wires to overheat. Don't jump with just a piece of wire.