P1914 Transmission Fluid Temp Sensor Circuit
The P1914 code indicates that the Powertrain Control Module (PCM) has detected an open circuit or a short to battery voltage (B+) or ground (GND) in the Transmission Fluid Temperature (TFT) sensor circuit. The TFT sensor is typically a negative temperature coefficient (NTC) thermistor that changes resistance based on transmission fluid temperature, allowing the PCM to adjust shift schedules, line pressure, and torque converter clutch engagement. When the circuit is open or shorted, the PCM receives a voltage outside the expected range and cannot determine the actual fluid temperature, potentially triggering fail-safe or limp-in modes.
01. Most Common Causes
- Faulty TFT sensor with internal damage or out-of-spec resistance values
- Open circuit, short to ground, or short to power in the sensor wiring
- Corroded, oil-contaminated, or damaged connector pins (bent, loose, or pushed back)
- Excessive resistance at splices or terminals due to oxidation or poor contact
- Harness chafing against hot components (exhaust, engine block) causing insulation breakdown
- Intermittent or internal PCM failure (rare)
02. Symptoms You Will Notice
- Illuminated Check Engine Light (MIL)
- Harsh or delayed shifts, erratic shifting, or transmission stuck in a single gear (limp mode)
- Torque converter clutch may not engage properly
- Reduced fuel economy and performance
03. Step-by-Step Diagnosis
Scan for codes and record freeze frame data; check for other transmission-related codes
Visually inspect the TFT sensor connector and wiring for damage, corrosion, or contamination
Measure TFT sensor resistance at the connector and compare to manufacturer specifications for the expected fluid temperature
Check for continuity, shorts to ground, and shorts to power in the wiring between the sensor and PCM
If wiring and sensor test OK, suspect a PCM fault; perform a PCM pin-out test or consult a specialist
1. Frequently Asked Questions
Is it safe to drive?▼
You can drive short distances, but the transmission may operate in a fail-safe mode, causing harsh shifts or reduced performance. Prolonged driving could lead to transmission damage due to incorrect line pressure or overheating. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, including a new TFT sensor ($30–$100) and labor (1–2 hours). If wiring repair is needed, costs may be higher. PCM replacement is rare and can exceed $800.