Transmission Fluid Temperature Sensor Circuit High Input
The P0713 code indicates that the transmission control module (TCM) has detected a voltage signal from the transmission fluid temperature (TFT) sensor that is higher than the expected range, typically above 4.5 volts. This sensor is a thermistor that changes resistance with temperature; a high voltage reading suggests either an open circuit, a faulty sensor, or a wiring issue. The TCM uses this input for shift scheduling, line pressure control, and torque converter lockup. A high input can cause the TCM to default to a safe mode, potentially leading to harsh shifts or limp mode.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or erratic shifting
- Transmission stuck in limp mode or failsafe
- Poor fuel economy
2. Most Common Causes
- Faulty transmission fluid temperature sensor
- Open or shorted wiring in the TFT sensor circuit
- Poor electrical connection at the sensor or TCM
- Corroded or damaged connector pins
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the TFT sensor connector and wiring for damage or corrosion.
Step 3: Measure the TFT sensor resistance at different temperatures and compare to specifications.
Step 4: Check for voltage at the sensor connector with the ignition on; should be around 5V reference.
Step 5: Test continuity and shorts in the wiring between the sensor and TCM.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the transmission may shift poorly or enter limp mode, potentially causing further damage.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for a sensor replacement, plus diagnostic time. Wiring repairs may add to the cost.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.