P0701 - TRANSMISSION CONTROL SYSTEM RANGE / PERFORMANCE

Modern vehicle automatic transmissions are monitored by various sensors and are also controlled by solenoids and regulators. All of these electronic components, which are necessary for the transmission to function properly, are housed in the TCM (Transmission Control Module).

Like the vehicle’s other modules, the TCM looks for feedback on some electrical signals when a solenoid is activated. In this way, it determines if any component has malfunctioned, at which time the TCM sets a DTC code.

In this case, the P0701 OBDII diagnostic code refers to a fault in the transmission control system. This fault is not specific, therefore, a diagnostic test is necessary to determine the cause.

• Check Engine light illuminates.
• Transmission shift patterns are erratic.
• The transmission is faulty when shifting.
• The fuel economy is affected.
• Transmission slips.
• Other transmission-related codes may be present.

The P0701 OBD2 error code is set due to the following:

• A low fluid condition due to transmission leaks.
• Transmission sensors may have failed.
• Circuits belonging to the transmission control system may be open or shorted.
• Torque Converter Clutch (TCC) may have been damaged.

When troubleshooting problems related to the P0701 OBDII fault code you should do the following:

• Since this code can refer to any fault in the system if there are other transmission codes set you must fix them before any diagnosis.
• Check the wiring harness that goes between the ECM (Engine Control Module) and TCM (Transmission Control Module). There could be an open or short circuit between them. If you find damage, repair it.
• Inspect both the ECM and TCM connector. These may have bent pins, or the presence of water causing corrosion.
• If the Transmission Control Module and Engine Control Module are located in the same unit, there is an electrical failure of the module. Therefore, flash programming if applicable, or replacement of the unit is necessary.