Technical Description of OBD-II Trouble Code
Malfunction in the Transmission Control System (TCS)
This diagnostic trouble code (DTC) is a generic powertrain code that is applicable to vehicles equipped with OBD-II. While it is a generic code, the specific repair steps may vary depending on the make and model of the vehicle.
What does this mean?
Many vehicles have a control module for the automatic transmission known as the transmission control module (TCM). The engine control module (ECM) communicates with the TCM to monitor the automatic transmission for faults. If the TCM detects a fault in the automatic transmission and sets a fault code related to the transmission, the ECM is also notified and sets a P0700 code in its memory.
This causes the Malfunction Indicator Lamp (MIL) to illuminate, indicating a problem to the driver. If this code is present and the MIL is illuminated, it means that there is at least one transmission code stored in the TCM’s memory. P0700 is an informational code only and does not indicate a specific fault in the engine, but rather a general fault in the transmission. Further diagnosis is required to identify the specific transmission fault, which requires a scan tool capable of communicating with the transmission module.
Symptoms
Symptoms of a P0700 DTC may include:
Causes
In most cases, this code is triggered by a problem with the transmission. The TCM detects the problem and sets the code. P0700 indicates that a fault code is stored in the TCM. However, this does not rule out the possibility of a failed PCM or TCM, although it is unlikely.
Possible Solutions
The only real solution for a P0700 code is to obtain a scan tool that can communicate with the transmission control module. Extracting the code from the TCM is the first step in repairing the transmission fault.
If a TCM-compatible scan tool is unable to communicate with the Transmission Control Module, it may indicate a fault with the TCM itself.
