P0855 - Drive Switch Input High

P0855 – OBD-II Trouble Code Technical Description

Drive switch input high

What does the fault code mean P0855?

Trouble code P0855 indicates a problem in the actuator switch input circuit. The code is stored when the engine control module (PCM) receives an incorrect signal from the overdrive/towing switch. This code applies to vehicles with four-wheel drive and automatic transmission. It is recommended to contact a car service to diagnose and fix the problem.

Possible reasons

Common causes of a P0855 code include an incorrectly adjusted transfer case range sensor, a damaged range sensor, or open or shorted wires or connectors. You should also consider using thread locking compound when installing the sensor mounting bolts to ensure a secure fit. Common problems that cause a P0855 code include a faulty shift lever assembly, a faulty transmission control module (TCM), wiring problems, a faulty operating switch, an open or shorted transmission switch harness, and a poor electrical connection in the control switch circuit.

What are the symptoms of a fault code? P0855?

Additionally, common symptoms associated with OBD code P0855 may also include the following:

• All-wheel drive failure
• Significantly rough gear shifting
• Complete lack of switching
• Decreased fuel efficiency

If you notice similar symptoms in your car, it is recommended to contact a car service to diagnose and solve the problem.

How to diagnose a fault code P0855?

To easily diagnose and resolve the P0855 code, follow these steps:

1. Use a scan tool (or code reader) along with a digital volt/ohm meter to diagnose the code condition.
2. Check the drive switch and its variable resistance located on the transfer case shift shaft, and check the switch contacts and voltage levels read by the PCM.
3. Visually inspect the wiring, connectors and system components, and replace or repair any damaged or corroded components.
4. Connect the scan tool to the diagnostic connector, record the stored trouble codes and freeze frame data to help with diagnosis.
5. Clear the codes and retest the vehicle to make sure they do not appear again. Check battery voltage and ground signals.
6. Test voltage and ground circuits using a digital volt/ohmmeter and replace and repair all system circuits/connectors as required.
7. Check the drive switch wiring diagram, test all associated circuits and the sensor for resistance and continuity, and compare the results to the manufacturer's specifications.
8. After replacing or repairing system circuits and components, retest the system to ensure a successful repair. If all circuits are within manufacturer specifications, the PCM may be damaged, requiring replacement and reprogramming.

Diagnostic errors

Common mistakes when diagnosing a P0855 code may include insufficient inspection of electrical wiring and connectors, improper adjustment or installation of the transfer case range sensor, and insufficient attention to testing and replacing faulty sensors. Errors may also occur due to improper evaluation or repair of shorted, open, or corroded electrical wires and connectors. For accurate diagnosis and troubleshooting, it is recommended to contact a qualified auto mechanic or service center.

How serious is the fault code? P0855?

Trouble code P0855 indicates problems with the drive switch input being high. Although this may cause some problems with gears and shifts working correctly, this code is not usually critical to driving safety. However, failure to diagnose and repair it can lead to problems with gear shifting and normal vehicle operation. It is recommended that you have a qualified auto mechanic diagnose and repair it as soon as possible to avoid potential transmission problems.

What repair will help eliminate the code? P0855?

To resolve the P0855 code, the following steps are recommended:

1. Check and, if necessary, adjust or replace an incorrectly installed transfer case range sensor.
2. Replace or repair the faulty range sensor. Check and correct any errors due to incorrect sensor installation.
3. Repair or repair all shorted, exposed or corroded electrical wires and connectors.
4. Replace or repair any corroded sensor connectors.

Parts Avatar Canada offers a wide range of automotive parts including PCM, Drive Switch, Shift Range Sensor, RPM, Automatic Transmissions Only, Electrical Connectors, Locking Compound, Automatics, Shift Solenoids, Shift Lever, Engine Timing Parts, Solenoids pressure controls, ignition timers, transmission shift solenoids, clutch cables, timing advance, elm repair and much more to help you repair your vehicle.

What is P0855 Engine Code [Quick Guide]