Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
Your car uses special switches called solenoids to help it change gears. This code means that one of these switches isn't getting enough power to work properly.
The P1804 code indicates that the powertrain control module (PCM) has detected a low voltage or open circuit condition in the shift solenoid 'D' circuit.
Shift solenoids are used in automatic transmissions to control the flow of transmission fluid, which in turn controls the engagement of the transmission gears. The 'D' solenoid is responsible for a specific gear range, and a 'circuit low' condition means there is insufficient voltage or an open circuit detected by the PCM.
• Transmission may not shift properly
• Check Engine Light is on
• Transmission stuck in a single gear
• Faulty shift solenoid 'D'
• Wiring issues such as damaged or corroded wires
• Poor electrical connections
• Faulty transmission control module (TCM)
PCM: Powertrain Control Module
TCM: Transmission Control Module
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the shift solenoid 'D' for proper operation.
• Repair or replace damaged wiring or connectors.
• Replace the shift solenoid 'D' if faulty.
• Replace or reprogram the TCM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Ford F-150
• Honda Accord
• Toyota Camry
• Regular transmission fluid changes
• Inspect wiring and connectors periodically
• Avoid harsh driving conditions
Transmission Issue
• Avoid driving at high speeds until repaired.
• Have the vehicle inspected by a professional mechanic.
Check if the vehicle's powertrain warranty covers transmission components.
This code is commonly associated with transmission issues in older vehicles with higher mileage.
Moderate – It is advisable to address this issue soon to avoid potential transmission damage.
Driving with transmission issues can be unsafe and may lead to further vehicle damage.
• Vehicle at operating temperature
• Transmission in drive mode
The shift solenoids are located inside the transmission, typically accessible by removing the transmission pan.
Q: Can I drive with a P1804 code?
A: It's not recommended to drive for long periods with this code, as it could lead to further transmission damage.
Q: How do I know if the shift solenoid is bad?
A: Symptoms include erratic shifting, stuck gears, and the Check Engine Light being on.
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