P0843 on 2007-2012 Acura RDX — Transmission Fluid Pressure Sensor/Switch 'A' Circuit High
1 vehicles · 1 makes · $150-$500 repair
How to diagnose and fix P0843: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Acura RDX · 2007–2012
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)
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P0843 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 P0843 mean?
P0843 stands for "Transmission Fluid Pressure Sensor/Switch 'A' Circuit High." The transmission fluid pressure sensor/switch 'A' circuit voltage is above the expected range (too high / open or shorted to power).
What are the most common causes of P0843?
The most common causes of P0843 are: Sensor circuit open or shorted to voltage, Faulty pressure sensor/switch A, Corroded/damaged connector, Internal TCM fault. The specific cause varies by vehicle.
How much does it cost to fix P0843?
Repair costs for P0843 range from $150 to $500, depending on the vehicle and root cause.
Which vehicles are affected by P0843?
Au7o has documented P0843 across 1 vehicle models from 1 manufacturers: Acura.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.