OBD II Fault Code
Fault Code Definition
- Transmission Range Sensor Circuit Range/Performance
The purpose of the automatic transmission is to match the engine's optimum power and torque characteristics to the driver's desired rate of acceleration and speed by auto-selecting different gear ratios or 'speeds' to power the wheels. The Transmission Range Sensor (also referred to as the PRNDL input and/or neutral safety switch) tells the transmission control module (TCM) and the powertrain control module (PCM) that the transmission is in park, reverse, neutral, drive, low, 2nd, 3rd etc. It is attached directly to the manual valve of transmission, so when the shift lever is moved say from park to drive, the Transmission Range Sensor communicates this critical information to the above mentioned vehicle computer systems.
Many vehicles have a control module for the automatic transmission called a 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 transmission related fault code, the ECM is informed of this also and sets a P0700 in the ECM memory.