Transmission Temperature Sensor 1 - Voltage Above Normal
Transmission temperature sensor is reading too high a voltage.
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What it means (plain English)
The transmission has a sensor that checks how hot it is, and if this sensor sends back a signal that's too high, the computer thinks the transmission is overheating.
What the computer is actually seeing
The Transmission Control Module (TCM) sees a voltage from the temperature sensor that is above 4.5 volts, which indicates a possible sensor malfunction or wiring issue.
What a healthy reading looks like
The expected voltage range from the transmission temperature sensor should be between 0.5 volts and 4.5 volts when the transmission is operating normally.
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.
- 11. Check the wiring and connectors at the transmission temperature sensor for damage or corrosion. Repair or replace as necessary. Decision: If connections are fine, proceed to next step.
- 22. Measure the voltage at the transmission temperature sensor with the engine running and under normal operating conditions. Expected: Voltage between 0.5V - 4.5V. Decision: If voltage is above 4.5V, replace the sensor; if normal, check the TCM.
- 33. If sensor replacement did not change the reading, check for continuity between the sensor and TCM. Decision: If continuity is good, consider a faulty TCM; if no continuity, repair the wiring.
Common causes
- Faulty transmission temperature sensor
- Wiring issues or short circuits in the sensor circuit
- Poor electrical connections at the sensor or TCM
- Faulty Transmission Control Module (TCM)
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not ideal to drive as it can indicate overheating, which could damage the transmission.
Will the code come back after clearing it?
If the underlying issue isn't fixed, yes, it will return.
Why is this code showing alongside SPN 1569?
SPN 1569 often relates to transmission overheating; if both are present, it indicates serious transmission issues.
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