Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's computer is saying that a sensor inside the transmission is reading a temperature that's too cold.
This code indicates that the Transmission Control Module (TCM) is detecting an abnormally low temperature reading from its internal temperature sensor labeled 'B'.
The P188A code is triggered when the TCM's internal temperature sensor 'B' reports a temperature that is below the expected range. This sensor helps the TCM manage transmission operations by monitoring the temperature of the transmission fluid. A reading that is too low might indicate a sensor fault or an issue with the transmission fluid temperature.
• Check Engine Light is on
• Transmission may not shift properly
• Poor fuel economy
• Transmission overheating warning
• Erratic transmission behavior
• Faulty TCM internal temperature sensor
• Wiring issues such as shorts or open circuits
• Faulty TCM
• Low transmission fluid level
• Cold ambient temperatures affecting sensor readings
TCM: Transmission Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Scan the vehicle for additional codes
• Inspect the wiring and connectors for damage or corrosion
• Check the transmission fluid level and condition
• Test the TCM temperature sensor for proper operation
• Verify the TCM functionality
• Repair or replace damaged wiring or connectors
• Replace the TCM internal temperature sensor
• Refill or replace transmission fluid if necessary
• Replace the TCM if faulty
• OBD-II scanner
• Multimeter
• Transmission fluid level gauge
• Basic hand tools
$150 - $800
Moderate
• Ford F-150
• Chevrolet Silverado
• Toyota Camry
• Regular transmission fluid checks
• Routine vehicle maintenance
• Avoid driving in extremely cold conditions without warming up the vehicle
Sensor Issue
• Have the vehicle inspected by a professional if the Check Engine Light is on
• Avoid heavy towing or driving until the issue is resolved
• Monitor transmission performance and fluid levels regularly
Check with your vehicle manufacturer, as some powertrain warranties may cover TCM-related issues.
This code has been reported in vehicles with high mileage or those operated in extremely cold climates.
Moderate – While the vehicle may still be operable, it is advisable to address this issue to prevent further transmission damage.
Ignoring this issue may lead to transmission damage, which could be costly to repair. Always address Check Engine Light warnings promptly.
• Vehicle at operating temperature
• Stable ambient conditions
The TCM is typically located near the transmission or integrated within the transmission housing.
Q: Can I drive my car with a P188A code?
A: While you may be able to drive, it's not recommended as it could lead to more severe transmission issues.
Q: How do I know if my transmission fluid is low?
A: You can check the transmission fluid level using the dipstick, usually located near the back of the engine bay.
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