Transmission Temperature Sensor 1
This code indicates a problem with the transmission temperature sensor.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The transmission temperature sensor measures how hot the transmission fluid is to prevent overheating. If it fails, the transmission may run hotter than it should, leading to damage.
What the computer is actually seeing
The ECU monitors the voltage from the transmission temperature sensor. Normal operation shows a voltage between 0.5V and 3.5V, which corresponds to temperature readings from -40°C to 150°C.
What a healthy reading looks like
Sensor output should be between 0.5V (cold) and 3.5V (hot).
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Check the wiring and connectors for damage or corrosion near the transmission temperature sensor.
- 2Ensure the transmission fluid is at the correct level and is not contaminated.
- 3Measure the voltage at the transmission temperature sensor connector; it should be between 0.5V to 3.5V with the engine running.
- 4If the voltage is out of range, replace the transmission temperature sensor. If it’s good, check the wiring harness for shorts or opens.
Common causes
- Faulty transmission temperature sensor
- Wiring issues between sensor and ECM
- Fluid contamination
- Faulty engine control module (ECM)
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; you can drive it but monitor transmission temperature closely.
Will this code come back after clearing it?
If the issue isn't fixed, yes, the code will reappear.
Why does it pair with SPN 1700?
SPN 1700 refers to a general failure of the transmission temperature sensor system.
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