The P1590 code on a Mitsubishi Outlander indicates a communication error between the Transmission Control Module (TCM) and the Engine Control Module (ECM). This error often triggers a “limp mode,” preventing the vehicle from shifting gears properly. This article outlines a personal experience with the P1590 code in a Mitsubishi Evo MR with a TC-SST transmission and the successful resolution using a re-teach procedure. While the specific vehicle differs, the P1590 code relates to the same communication error and may offer valuable insight for Outlander owners.
Understanding the P1590 Code
The P1590 code signifies a problem with the communication network between the TCM and ECM, specifically concerning a torque reduction request. This disruption can lead to various drivability issues, including the inability to shift gears, as experienced in the Evo MR scenario. The accompanying U0101 code, indicating a TCM timeout, further supports a communication breakdown. In the case of the Evo MR, shifting into neutral at speed and then back into drive seemed to trigger the error. While the exact trigger for an Outlander might differ, understanding the underlying communication issue is crucial.
Diagnosing the P1590 Code in a Mitsubishi Outlander
When faced with a P1590 code in your Mitsubishi Outlander, start with a thorough inspection:
- Check for obvious issues: Inspect for loose connections, damaged wiring, or blown fuses related to the TCM and ECM.
- Fluid levels: Ensure the transmission fluid is at the correct level and in good condition. Low or contaminated fluid can contribute to transmission problems.
- Diagnostic tools: Use a professional-grade OBD-II scanner or Mitsubishi-specific software like MUT-III to read and confirm the error codes. This will help rule out other potential issues.
Resolving the P1590 Code: The Re-learn Procedure
In some cases, like the Evo MR example, a TCM re-learn procedure can resolve the P1590 code. This process involves resetting the TCM and allowing it to relearn the proper communication protocols with the ECM.
- Professional Assistance: While the Evo MR owner performed the re-teach independently using resources found online, it’s generally recommended to have this procedure done by a qualified Mitsubishi technician. They possess the necessary software and expertise to perform the re-learn correctly.
- Software and Procedure: The specific software and steps for a TCM re-learn vary depending on the Outlander model year. Consult the official Mitsubishi service manual or a reputable online resource for detailed instructions.
Conclusion: Addressing the P1590 Code
The P1590 code in a Mitsubishi Outlander indicates a serious communication error that can significantly impact drivability. While a TCM re-learn procedure might prove successful, seeking professional diagnosis and repair is crucial. A qualified technician can accurately diagnose the root cause and perform the necessary repairs to ensure the long-term health of your Outlander’s transmission system. Ignoring the P1590 code can lead to further damage and more costly repairs down the line. Addressing it promptly will get you back on the road safely and efficiently.
