Check engine light on

Hello,

If your Malfunction Indicator Lamp[MIL] or "check engine" lamp is illuminated then you can pull the Direct Trouble Code[DTC] by plugging a code reader into the Data Link Connector[DLC]. Here is a link below with a guide explaining how to do this:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please go through this guide and get back to us with the DTC and we can provide you with specific instructions on what is wrong and how to fix it.

Thanks,
Alex
2CarPros

Got the codes:

P0700 Transmission Control System (MIL request)
P0731 Gear 1 Incorrect ratio
P0755 Shift Solenoid B

These are the services I had done before the light came back on:

Transmission Fluid Service
Automatic Transmission Fluid Service
Automatic Transmission Shift Solenoid

So is it safe to say the guy diagnosed the right things but didn't do the job right?

Hello,

In the diagrams down below I have included the diagnostic troubleshooting guides from the vehicle manufacturer for tracking down and fixing each of the DTC's listed from your reply. Please go through these guides and get back to us with what you find.

Thanks,
Alex
2CarPros

I had someone suggest it was a bad PCM, do you think so?

Hello again,

No, I don't think so. If a control module was to blame, it would be the Transmission Control Module[TCM] and not the Powertrain Control Module[PCM]. The PCM is basically a fuel injection computer that gets inputs from sensors and then makes variations to a preprogrammed fuel and ignition map from the various sensor inputs and then sends output signals to the spark plugs and fuel injectors when to properly turn on to keep the engine running properly. If you want a list of possible causes, each DTC has a list of possible causes right after the description of what's going on.

Thanks,
Alex
2CarPros

So is the TCM not connected to PCM? Have been seeing similar articles online connecting my symptoms to PCM.. And the guy that I spoke to after initial diagnosis has solved weird issue with previous car so inclined to heed his advice.

Also, how do I get the specific PCM part number?

Hello again,

Okay. The diagrams that I sent earlier are from the vehicle manufacturer with instructions and explanations of what specifically is going on with the DTC's for your vehicle. So if your guy knows more about it than the company that designed and built the vehicle than I would also would go with him. As far as getting a specific PCM part number they go by what is called the vehicle strategy. This is the specific programming that the PCM has and differs from vehicle to vehicle. You should be able to find a sticker on the PCM in your vehicle with the strategy number on it.

Thanks,
Alex
2CarPros