Fix P0855: STEP-BY-STEP diagnostic GUIDE!

The P0855: Drive Switch Input Circuit High refers to a condition where the drive switch input circuit is detecting higher-than-expected voltage. This can lead to improper detection of the drive mode, potentially causing issues with shifting or transmission performance. The problem could arise from a faulty drive switch, wiring issues, or a malfunction in the transmission control module (TCM).

P0855 – Quick Overview

CodeInformation
MeaningP0855: Drive Switch Input Circuit High
Is it serious?Yes, this can cause incorrect drive mode detection, leading to shifting or transmission issues.
Possible causes– High voltage in the drive switch input circuit
– Faulty switch or wiring
– Faulty transmission control module (TCM)
How to diagnose?– Test the circuit for high voltage
– Inspect wiring and connectors
– Replace faulty components if needed

P0855 Meaning

The P0855: Drive Switch Input Circuit High code indicates that the voltage in the drive switch input circuit is higher than the specified range. This high voltage can cause incorrect detection of the drive mode, leading to transmission shifting problems or failure to engage the correct gear.

Step-by-step diagnostic guide

ActionDescriptionTools Needed
Check for Other CodesUse an OBD-II scanner to check for any additional related codes for further insights into the transmission or drive switch issue.OBD-II Scanner
Inspect Drive SwitchVisually inspect the drive switch for signs of damage, wear, or misalignment.Flashlight, Safety Gloves
Test the Circuit for High VoltageUse a multimeter to measure the voltage in the drive switch input circuit and compare it to manufacturer specifications.Multimeter
Check Wiring and ConnectorsInspect the wiring and connectors for any signs of damage, corrosion, or loose connections that could cause high voltage in the circuit.Flashlight, Multimeter
Replace Faulty ComponentsIf the switch, wiring, or connectors are faulty, replace the components to restore proper voltage levels and circuit function.Replacement Parts, Basic Tools
Clear the Code and Test DriveAfter completing repairs, clear the code using an OBD-II scanner and take the vehicle for a test drive to ensure proper operation.OBD-II Scanner, Vehicle Owner’s Manual
Recheck for CodesAfter the test drive, re-scan the system to confirm that the P0855 code does not return.OBD-II Scanner
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