P085B — Gear Shift Control Module B Communication Circuit Low

What Does P085B Mean?

P085B is a diagnostic trouble code indicating: Gear Shift Control Module B Communication Circuit Low. This code relates to the transmission system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P085B

⚠️ Check Engine Light (MIL) illuminated
⚠️ Gear Shift Control Module B Communication reading at zero or minimum value
⚠️ Related system not functioning or in fail-safe mode
⚠️ Harsh or delayed shifting

Common Causes

🔍 Open or broken wire in Gear Shift Control Module B Communication circuit
🔍 Poor ground connection at Gear Shift Control Module B Communication
🔍 Faulty Gear Shift Control Module B Communication with no output signal
🔍 Disconnected or loose Gear Shift Control Module B Communication connector
🔍 Blown fuse in related circuit

Frequently Asked Questions

What does P085B mean?

P085B indicates: Gear Shift Control Module B Communication Circuit Low. The vehicle's computer has detected that the Gear Shift Control Module B Communication is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P085B?

Only short distances if absolutely necessary. P085B affects a critical system and should be diagnosed within a few days to avoid further damage.

How much does it cost to fix P085B?

Repair costs for P085B typically range from $20 to $500, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.

What To Do Next

Possible Fixes

🔧 Repair broken wire or restore ground in Gear Shift Control Module B Communication circuit
🔧 Clean and secure Gear Shift Control Module B Communication connector and ground points
🔧 Replace failed Gear Shift Control Module B Communication

1
Find your vehicle above
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P085B: Gear Shift Control Module B Communication Circuit Low