What Does P1805 Mean?
DTC P1805 indicates a circuit failure in the transmission clutch interlock safety switch, similar to P1800 but often manufacturer-specific to a different circuit path or redundant switch. The PCM cannot reliably determine clutch pedal position, affecting the starter engagement interlock and potentially transmission shift logic.
Common Causes
30%
Failed clutch interlock safety switch
25%
Open or damaged wiring in the secondary clutch switch circuit
20%
Corroded connector at the clutch switch
15%
Clutch pedal assembly wear preventing full switch engagement
10%
PCM/TCM input circuit failure
Diagnostic Steps
1
Identify which specific clutch switch circuit this code references for your vehicle using manufacturer service information.
2
Test the clutch interlock switch with an ohmmeter while manually actuating the plunger to verify proper open/close operation.
3
Inspect the switch connector and wiring for damage, corrosion, or disconnection.
4
Check the clutch pedal bracket for proper switch mounting and alignment; ensure the plunger fully contacts the pedal arm.
5
Verify continuity from the switch to the PCM on the signal wire and check for proper ground path.
Estimated Repair Cost
$30 - $250
Parts + labor, varies by vehicle and location
DTC P1805 indicates a circuit failure in the transmission clutch interlock safety switch, similar to P1800 but often manufacturer-specific to a different circuit path or redundant switch. The PCM cannot reliably determine clutch pedal position, affecting the starter engagement interlock and potentia...
The most common cause of P1805 (Transmission Clutch Interlock Safety Switch Circuit Failure) is: Failed clutch interlock safety switch
Typical repair costs for P1805 range from $30 to $250, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A non-functional clutch interlock can allow engine cranking in gear, creating a vehicle lurch hazard, or may prevent starting entirely.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1805 to identify the root cause.
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Quick Info
Category
Powertrain
System
Starting System / Transmission
Difficulty
Type
Manufacturer
Recommended Tools
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