P078D — Shift Timing Solenoid B High

What Does P078D Mean?

P078D is a diagnostic trouble code indicating: Shift Timing Solenoid B High. This code relates to the transmission system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P078D

⚠️ Check Engine Light (MIL) illuminated
⚠️ Shift Timing Solenoid B High not functioning as expected
⚠️ Related system may be in fail-safe mode
⚠️ Harsh or delayed shifting

Common Causes

🔍 Faulty Shift Timing Solenoid B High
🔍 Wiring or connector issue in Shift Timing Solenoid B High circuit
🔍 Related mechanical or electrical fault
🔍 ECM/PCM issue (rare)

Frequently Asked Questions

What does P078D mean?

P078D indicates: Shift Timing Solenoid B High. The vehicle's computer has detected that the Shift Timing Solenoid B High is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P078D?

Only short distances if absolutely necessary. P078D affects a critical system and should be diagnosed within a few days to avoid further damage.

How much does it cost to fix P078D?

Repair costs for P078D typically range from $150 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

🔧 Inspect Shift Timing Solenoid B High and related wiring
🔧 Replace faulty Shift Timing Solenoid B High

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.

P078D: Shift Timing Solenoid B High