The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2016 G90 5.0L Transmission Limp Mode - P0700 Code

0

Mike T. · rep 0 · May 25, 4:34 AM · 1 replies · solved · Question

Vehicle: 2016 Genesis G90 5.0L

Hello fellow Genesis owners,

My 2016 Genesis G90 5.0L recently started acting up with its transmission. While driving, it suddenly went into what felt like limp mode – stuck in a higher gear, very sluggish acceleration, and the check engine light came on. I pulled over, shut it off, and restarted it, and the issue went away temporarily, but it keeps coming back.

I managed to get it home and scan it. It's showing a P0700 code: 'Transmission Control System Malfunction'. There are no other specific transmission codes (like P07xx) showing up yet, just the generic P0700.

Has anyone with a G90 experienced this? What was the cause? I'm worried about the transmission itself, but I'm hoping it might be something simpler like a sensor or fluid issue. Any guidance on where to start troubleshooting would be greatly appreciated!

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 25, 4:34 AM

0

ClearTheCode admin answer:

The P0700 code on your 2016 Genesis G90 5.0L indicates that the Transmission Control Module (TCM) has detected a fault within the transmission system and has illuminated the check engine light. This code is a general informational code, meaning there are usually more specific transmission-related fault codes stored in the TCM that your basic scanner might not be able to read. These specific codes are crucial for proper diagnosis.

Here's a diagnostic path for your issue:

  1. Check Transmission Fluid Level and Condition: This is the easiest first step. Refer to your owner's manual for the correct procedure to check the transmission fluid (usually with the engine warm and running, in Park). Low fluid levels can cause shifting issues, overheating, and limp mode. Also, note the fluid's color and smell. Burnt-smelling or dark, murky fluid indicates a problem.
  2. Scan for Specific Transmission Codes: A standard OBD-II scanner often only reads generic P-codes from the Engine Control Module (ECM). To get to the root of the P0700, you'll need a more advanced diagnostic scanner capable of communicating with the TCM to retrieve specific P07xx codes. These codes will pinpoint the exact fault, such as a faulty shift solenoid, speed sensor, or pressure switch.
  3. Inspect Wiring and Connectors: Faulty wiring or corroded connectors to the transmission, TCM, or various sensors can cause intermittent issues and trigger fault codes. Visually inspect all accessible wiring harnesses and connectors for damage or looseness.
  4. Transmission Solenoids: Many transmission issues, including erratic shifting or limp mode, are caused by failing shift solenoids. These are electronically controlled valves that direct fluid flow within the transmission. A specific P07xx code would usually point to a particular solenoid.
  5. Transmission Control Module (TCM): While less common, a faulty TCM itself can cause a wide range of transmission problems. This is usually diagnosed after ruling out other components.

When to See a Shop:

  • Immediately, if your basic scanner cannot read the specific P07xx codes from the TCM. A professional diagnosis with an advanced scanner is essential.
  • If your transmission fluid is low, burnt, or contains debris, indicating internal wear or a leak.
  • If you suspect a faulty solenoid, sensor, or the TCM itself, as these require specialized tools and expertise for diagnosis and replacement.
  • If the vehicle remains stuck in limp mode or the issue becomes constant, to prevent further damage to the transmission.
Menu

Help & account