P1804 Hold Switch Circuit Malfunction
The P1804 code indicates a malfunction in the hold switch circuit, which is specific to Nissan and Infiniti vehicles with automatic transmissions. The hold switch allows the driver to lock the transmission in a specific gear, preventing automatic shifting. When the Transmission Control Module (TCM) detects an abnormal, missing, or out-of-range electrical signal in the hold switch circuit, it sets this code. This can prevent the hold mode from functioning correctly.
01. Most Common Causes
- Faulty or worn hold switch
- Open, shorted, or high-resistance wiring in the hold switch circuit
- Corroded, loose, or moisture-damaged hold switch connector
- Internal TCM failure
- Blown fuse related to the hold switch circuit
02. Symptoms You Will Notice
- Hold mode does not engage or disengage
- Transmission may not hold gear as selected
- Check Engine Light or transmission warning light illuminated
03. Step-by-Step Diagnosis
Scan for codes and verify P1804 is present
Inspect the hold switch and its connector for damage, corrosion, or loose pins
Test the hold switch for proper continuity and resistance per manufacturer specs
Check wiring and connectors between the switch and TCM for opens, shorts, or high resistance
If all else is good, test the TCM for proper operation or replace if necessary
1. Frequently Asked Questions
Is it safe to drive?▼
Yes, but the hold mode may not work. The vehicle can still be driven in normal automatic mode. However, if the transmission shifts erratically, have it inspected promptly.
How much does it cost to fix?▼
Typically between $100 and $400, depending on whether the switch, wiring, or TCM needs repair or replacement.