P0701 – Transmission control system -range/performance problem

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By Benjamin Jerew (Contact Me)
Last Updated 2015-11-27
ASE Master Tech
CodeFault LocationProbable Cause
P0701 Transmission control system -range/performance problem
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Table of Contents

  1. What Does Code P0701 Mean?
  2. What are the common causes of code P0701 ?
  3. What are the symptoms of code P0701 ?
  4. How do you troubleshoot code P0701 ?
  5. Codes Related to P0701
  6. Get Help with P0701

What Does Code P0701 Mean?

Like the rest of the modern automobile, the most basic of which have more processing power than the original Space Shuttle, the modern automatic transmission is monitored by numerous sensors and controlled by a number of solenoids and regulators. The TCM (transmission control module) houses all the electronics required for proper automatic transmission operation.

Like the ECM (engine control module) and other vehicle modules, the TCM looks for feedback, within certain thresholds, when it activates a solenoid, for example. Anything outside the expected parameters is determined to be a fault, at which time the TCM sets a DTC (diagnostic trouble code). The ECM, with which the TCM may or may not be integrated, depending on year, make, and model, sets a TCM informational DTC and illuminates the MIL (malfunction indicator lamp).

DTC P0701 refers to a generic transmission control system fault, but not to a specific fault, such as a solenoid or brake, for example. On encountering DTC P0701 in ECM memory, further diagnosis will be required to determine the nature of the fault.


What are the common causes of code P0701 ?

Depending on year, make, and model, DTC P0701 may have number of causes. Here are some of the most common.

  • Wiring Harness or Connectors – Damage and corrosion are the two leading causes of TCM faults. A broken connector or compromised weather pack can easily allow water entry or poor connection.
  • Aftermarket Installations – Inadvertently tapping into a critical circuit may cause unwanted interference in ECM / TCM communication.

What are the symptoms of code P0701 ?

Depending on the vehicle, symptoms related to DTC P0701 may range from an illuminated MIL, with no drivability issues, to serious drivability issues.

Depending on failsafe design, some vehicles may revert to hydraulic function and shift more or less as expected, while others may drop certain gears, such as being unable to shift out of “L” to upper gears, or running only in 2nd gear. Some vehicles may be difficult to start, act like they’re misfiring, and may even stall when coming to a stop.

In any case, with the MIL illuminated, the ECM is automatically put in “limp-home mode,” enabling you to get home, but fuel economy and drivability will suffer. Immediate diagnosis and repair will be necessary.


How do you troubleshoot code P0701 ?

DTC P0701 is most often linked to one of two things: Electrical Failure or TCM Failure. First, make sure that both the ECM and TCM have good power and ground connections.

  • If the TCM is a separate module from the ECM
    • Check the wiring harness between the ECM and TCM. This may take some time, but there is likely an open circuit or short circuit between them. Look for obvious damage, such as crushed wires, rodent damage, or road debris damage.
    • Check the connectors at the ECM and TCM. Look for broken or bent pins, which would cause open circuits or short circuits. Also look for corrosion or water entry, which could cause similar problems.
    • Barring electrical problems, you likely have a TCM failure, which would require a reflash, if applicable, or replacement of the unit.
  • If the TCM and ECM are in the same unit, then an electrical fault is essentially a module fault, which would require a reflash, if applicable, or replacement of the unit. Again, look for broken or bent pins, corrosion, water entry, or damage, any of which could cause this type of fault.

DTC P0701 may also simply refer to another fault in the system, so scan for additional related transmission control system codes for further diagnosis.

If the ECM shows DTC P0701 stored, look for other TCM-related codes to aid in your diagnosis. You may find:

  • P0613 TCM Processor
  • P0614 ECM/TCM Incompatible
  • P0706 Transmission Range Sensor Circuit Range/Performance
  • U0101 Lost Communication With Transmission Control Module

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