The P085C: Gear Shift Control Module ‘B’ Communication Circuit High refers to a condition where the communication circuit for gear shift control module ‘B’ is detecting higher-than-expected voltage. This issue can prevent proper communication between the gear shift control module and the vehicle’s transmission system, causing shifting problems. The root causes can include faulty wiring, connector issues, or a malfunctioning gear shift control module or transmission control module (TCM).
P085C – Quick Overview
| Code | Information |
|---|---|
| Meaning | P085C: Gear Shift Control Module ‘B’ Communication Circuit High |
| Is it serious? | Yes, it can cause shifting problems and affect transmission operation. |
| Possible causes | – High voltage in the gear shift control module ‘B’ communication circuit – Faulty module 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 |
P085C Meaning
The P085C: Gear Shift Control Module ‘B’ Communication Circuit High code indicates that the voltage in the communication circuit for gear shift control module ‘B’ is above the expected range. This high voltage can interfere with the module’s ability to communicate properly with the transmission system, potentially leading to improper shifting or transmission malfunctions.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for additional codes related to communication or transmission issues. | OBD-II Scanner |
| Inspect Gear Shift Control Module | Visually inspect gear shift control module ‘B’ for signs of damage, misalignment, or loose connections. | Flashlight, Safety Gloves |
| Test the Circuit for High Voltage | Use a multimeter to measure the voltage in the communication circuit of gear shift control module ‘B’ and compare it to manufacturer specifications. | Multimeter |
| Check Wiring and Connectors | Inspect the wiring and connectors for signs of damage, corrosion, or loose connections that may be causing high voltage. | Flashlight, Multimeter |
| Replace Faulty Components | If the module, wiring, or connectors are faulty, replace the necessary components to restore proper communication. | Replacement Parts, Basic Tools |
| Clear the Code and Test Drive | After repairs, clear the code using an OBD-II scanner and test the vehicle to ensure proper communication and shifting performance. | OBD-II Scanner, Vehicle Owner’s Manual |
| Recheck for Codes | After the test drive, re-scan the system to confirm that the P085C code does not return. | OBD-II Scanner |
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