P0847 on Acura: How to Diagnose & Fix
Transmission Fluid Pressure Sensor/Switch 'B' Circuit Low
1 Acura model · 1 documented issue · $150-$500 repair
P0847 on Acura by model: symptoms, diagnosis and fix
The 2007-2012 RDX's 5-speed automatic uses clutch pressure switches to confirm hydraulic apply of the 2nd and 3rd clutch packs. These switches are a recurring failure point on the first-generation car — the 3rd clutch switch most often. When one fails or its circuit shorts, the TCM sets P0847/P0848 and flags P0700 at the PCM, illuminating the check engine light and frequently the D light. The car may drop into a fail-safe gear pattern with harsh or limited shifting. This is an electrical/sensor failure, not internal clutch damage, and is regularly misquoted by shops as a transmission rebuild.
Common Symptoms
- Check engine light with P0700
- D indicator light blinking
- Harsh or limited shifting / fail-safe gear
- Loss of some forward gears
- No other driveability symptoms when cold
How to Fix
Scan the TCM (not just generic P0700) to identify which clutch pressure switch circuit is faulted. Inspect the connector and harness for oil wicking and corrosion first — a contaminated connector reproduces the same code. Replace the failed 2nd or 3rd clutch pressure switch (a screw-in switch on the transmission case) and change the fluid with genuine Honda ATF DW-1; do not substitute generic ATF, which degrades shift quality on this unit. No recall or warranty extension covers this.
Sources for this issue (2)
P0847 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0847 mean on a Acura?
P0847 stands for "Transmission Fluid Pressure Sensor/Switch 'B' Circuit Low." The transmission fluid pressure sensor/switch 'B' circuit voltage is below the expected range (too low / shorted to ground). On Acura it is documented across 1 model: RDX.
What are the most common causes of P0847?
The most common causes of P0847 are: Sensor signal shorted to ground, Faulty pressure sensor/switch B, Corroded/damaged connector, Internal TCM fault. The specific cause varies by vehicle.
How much does it cost to fix P0847 on a Acura?
Published repair estimates on Acura range from $150 to $500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0847 on a different make?
View P0847 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.