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
| Code | Information |
|---|---|
| Meaning | P0855: 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
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use 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 Switch | Visually inspect the drive switch for signs of damage, wear, or misalignment. | Flashlight, Safety Gloves |
| Test the Circuit for High Voltage | Use a multimeter to measure the voltage in the drive switch input circuit and compare it to manufacturer specifications. | Multimeter |
| Check Wiring and Connectors | Inspect 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 Components | If 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 Drive | After 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 Codes | After the test drive, re-scan the system to confirm that the P0855 code does not return. | OBD-II Scanner |
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