Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's system is saying that the part that cools the transmission fluid isn't working because no fluid is moving through it.
This code indicates that the vehicle's computer has detected no flow of transmission fluid through the cooler, which can lead to overheating and transmission damage.
The transmission fluid cooler is responsible for maintaining the temperature of the transmission fluid by dissipating heat. If the flow is obstructed or absent, the transmission can overheat, leading to potential failure. The code P1900 is triggered when the transmission control module (TCM) or powertrain control module (PCM) detects a lack of fluid flow in the cooler.
• Overheating transmission
• Transmission slipping
• Warning light on dashboard
• Blocked transmission fluid cooler
• Faulty transmission fluid pump
• Clogged transmission fluid lines
Transmission Fluid Cooler: A component that helps keep the transmission fluid at the correct temperature.
Transmission Control Module (TCM): An electronic device that controls transmission functions.
• Check transmission fluid level and condition
• Inspect transmission fluid cooler for blockages
• Test transmission fluid pump functionality
• Clear any blockages in the cooler
• Replace faulty transmission fluid pump
• Flush and replace transmission fluid
• OBD-II scanner
• Transmission fluid pressure gauge
• Basic hand tools
$150 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Dodge Ram
• Regular transmission fluid checks
• Routine maintenance of cooler
• Avoid overloading vehicle
Transmission Performance
• Avoid driving until the issue is resolved to prevent damage
• Consult a professional mechanic for a thorough inspection
Check with your vehicle manufacturer for specific warranty coverage related to transmission components.
This code has been associated with vehicles that have high mileage or those that frequently tow heavy loads.
High – Address immediately to prevent transmission damage.
Ignoring this issue can lead to severe transmission damage and potential safety hazards while driving.
• Engine running
• Transmission at operating temperature
The transmission fluid cooler is typically located at the front of the vehicle, near the radiator.
Q: Can I drive with a P1900 code?
A: It's not recommended to drive with this code active, as it can lead to transmission overheating and damage.
Q: How do I know if my transmission fluid cooler is blocked?
A: Signs of a blocked cooler include transmission overheating, slipping, and unusual noises.
Pro · Four-system diagnostics
A handheld scanner aimed at engine, transmission, ABS, and airbag diagnostic work.
Chassis and ABS faults usually need a scanner that can read brake-system data directly.
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