P3400: P34C8
What Does P3400 Mean?
P3400 is a diagnostic trouble code indicating: P34C8. This code relates to the powertrain system. It has been reported in NHTSA complaints across 4 different vehicle models.
Symptoms of P3400
- ⚠️ Check engine light illuminated
- ⚠️ Hesitation during acceleration
- ⚠️ Engine misfires
- ⚠️ Loss of engine power
- ⚠️ Abnormal exhaust smoke
- ⚠️ Unusual vibrations
Common Causes
- 🔍 Worn or fouled spark plugs
- 🔍 Torque converter malfunction
- 🔍 Sensor or control module malfunction
P3400 Reports by Year
Real Owner Reports
From NHTSA complaint database — actual owner descriptions.
"THE CHECK ENGINE LIGHT KEPT COMING UP WITH THE MAINTENANCE LIGHT AND THE OIL LEVEL KEPT DROPPING.I TOOK IT TO AUTOZONE AND I GOT THESE CODED P3497 AND P3400. I DID A RESEARCH MYSELF AND FOUND OUT THAT THERE WAS A RECALL ON THIS ISSUE AS STATED IN HONDA'S BULLETIN 11-033.THE RECALL COVERS ALL ACCORD"
— Honda Accord owner, 09/09/2018
"ACCORD V6 WITH VARIABLE CYLINDER MANAGEMENT (VCM). AT EXACTLY 65,000 MILES, IN EXPRESSWAY RUSH HOUR TRAFFIC, IMMEDIATE CATASTROPHIC POWER LOSS AND CHECK ENGINE LIGHT COMES ON. TOW TO HONDA DEALER. DEALER RECEIPT SHOWS CODE P3400 FOUND AND DEALER REPLACED REAR OIL PRESSURE SENSOR. CAR OWNER SUGGE"
— Honda Accord owner, 04/05/2017
"WHILE DRIVING AT HIGHWAY SPEED (55 MPH) AND THEN SLOWING DOWN FOR TRAFFIC, THE VARIABLE TIMING CONTROL ACTUATOR APPARENTLY STUCK. THE ENGINE WARNING LIGHT CAME ON FOLLOWED BY WHITE SMOKE FROM THE TAILPIPES. THERE WAS AN IMMEDIATE LACK OF POWER TRYING TO ACCELERATE AGAIN. THIS CONTINUED UNTIL THE "
— Honda Accord owner, 02/20/2019
Source: NHTSA Complaints Database
Most Reported Vehicles for P3400
Based on NHTSA owner complaint data.
| # | Vehicle | Reports |
|---|---|---|
| 1 | HONDA ODYSSEY | |
| 2 | HONDA ACCORD | |
| 3 | HONDA PILOT | |
| 4 | GMC YUKON |
P3400 Reports by Vehicle
Detailed NHTSA complaint analysis for each vehicle model.
Frequently Asked Questions
Can I drive with this code?
Will this code clear itself?
How do I find the exact cause?
What To Do Next
Possible Fixes
- 🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
- 🔧 Test the relevant sensor(s) with a multimeter before replacing
- 🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)
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1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
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3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.