P1839
Internal Mode Switch 'C' Circuit Low Voltage
P1839 is an OBD-II diagnostic trouble code meaning: Internal Mode Switch 'C' Circuit Low Voltage. Common causes: malfunction of the internal mode switch, open or short circuit in the wiring circuit. Estimated repair cost: $33–167.
Symptoms
- Incorrect display of automatic transmission selector position
- Transmission of the gearbox into emergency mode
- Gear shifting problems
- Check Engine Light Illuminates
- Uncertain switching between P-R-N-D modes
Causes
- Malfunction of the internal mode switch
- Open or short circuit in the wiring circuit
- Oxidation or poor contact in connectors
- Problems with the transmission control unit
- Mechanical damage to the wiring harness
How to Fix
- Checking the voltage in the switch circuit
- Inspecting the condition of wiring and connectors
- Testing the operation of the mode switch
- Replacing a faulty switch if necessary
- Updating the transmission control unit firmware (if necessary)
Related codes
FAQ
What does the P1839 code mean?
P1839 is an OBD-II diagnostic trouble code that indicates: Internal Mode Switch 'C' Circuit Low Voltage
What causes a P1839 error code?
The most common causes of P1839 include: Malfunction of the internal mode switch; Open or short circuit in the wiring circuit; Oxidation or poor contact in connectors; Problems with the transmission control unit.
How do I fix a P1839 diagnostic trouble code?
To fix P1839: Checking the voltage in the switch circuit. Inspecting the condition of wiring and connectors. Testing the operation of the mode switch. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P1839?
Limited driving only, diagnose soon
How much does it cost to fix P1839?
The estimated repair cost for P1839 is $33–167. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat