The P085B: Gear Shift Control Module ‘B’ Communication Circuit Low refers to a condition where the communication circuit for gear shift control module ‘B’ is detecting lower-than-expected voltage. This could result from faulty wiring, connector issues, or a malfunctioning gear shift control module or transmission control module (TCM). Proper communication voltage is necessary for the transmission to shift properly and for the vehicle to operate smoothly.
P085B – Quick Overview
| Code | Information |
|---|---|
| Meaning | P085B: Gear Shift Control Module ‘B’ Communication Circuit Low |
| Is it serious? | Yes, this can cause shifting problems and affect overall transmission performance. |
| Possible causes | – Low 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 low voltage – Inspect wiring and connectors – Replace faulty components if needed |
P085B Meaning
The P085B: Gear Shift Control Module ‘B’ Communication Circuit Low code indicates that the voltage in the communication circuit of gear shift control module ‘B’ is below the expected range. This low voltage can prevent the module from communicating properly with other vehicle systems, leading to transmission shifting problems.
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, wear, or loose connections. | Flashlight, Safety Gloves |
| Test the Circuit for Low Voltage | Use a multimeter to measure the voltage in the communication circuit of gear shift control module ‘B’ and compare it with manufacturer specifications. | Multimeter |
| Check Wiring and Connectors | Inspect the wiring and connectors for signs of damage, corrosion, or loose connections that could be causing low voltage. | Flashlight, Multimeter |
| Replace Faulty Components | If gear shift control module ‘B’, wiring, or connectors are found faulty, replace the necessary components to restore proper voltage. | 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 transmission and communication function. | OBD-II Scanner, Vehicle Owner’s Manual |
| Recheck for Codes | After the test drive, re-scan the system to confirm that the P085B code does not return. | OBD-II Scanner |
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