P0888: TCM Power Relay Sense Circuit
2 vehicles · 2 makes · $200-$4,800 repair
Most Reported On
P0888 is an OBD-II diagnostic trouble code meaning “TCM Power Relay Sense Circuit.” This code sets when the transmission control module (TCM) detects an incorrect voltage on the power relay sense circuit, which monitors whether the TCM power relay is supplying voltage as expected. If the relay or its sense circuit is faulty, the TCM cannot confirm it is properly powered to control the transmission. Symptoms can include shifting problems, the transmission entering failsafe mode, and a check engine light. The fault usually lies in the power relay, the sense wiring, or related connections. This code is most commonly reported on 1997-2011 Dodge Dakota, and 2007-2024 RAM 2500 (2500 6.7L Cummins (68RFE automatic)), with repair costs ranging from $200 to $4,800.
Common Causes
Typical Repair Cost
Based on 2 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P0888, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
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FAQ
What does P0888 mean?
P0888 stands for "TCM Power Relay Sense Circuit." This code sets when the transmission control module (TCM) detects an incorrect voltage on the power relay sense circuit, which monitors whether the TCM power relay is supplying voltage as expected. If the relay or its sense circuit is faulty, the TCM cannot confirm it is properly powered to control the transmission. Symptoms can include shifting problems, the transmission entering failsafe mode, and a check engine light. The fault usually lies in the power relay, the sense wiring, or related connections.
What are the most common causes of P0888?
The most common causes of P0888 are: Faulty TCM power relay, Open, shorted, or corroded sense-circuit wiring, Blown fuse in the power/relay circuit, Poor or loose connector at the relay or TCM, Poor ground connection, Low system voltage, Faulty TCM (less common). The specific cause varies by vehicle.
How much does it cost to fix P0888?
Repair costs for P0888 range from $200 to $4,800, depending on the vehicle and root cause.
Which vehicles are affected by P0888?
Au7o has documented P0888 across 2 vehicle models from 2 manufacturers: Dodge, RAM.
Sources (4)
- videoYouTube - How to Diagnose and Replace 42RE Overdrive Solenoid - ChrisFix
- article68RFE Transmission Guide: Problems & DIY Upgrades - Diesel Power Products
- article68RFE Transmission Problems & Solutions - Monster Transmission
- articleRam 2500 Transmission Problems: 68RFE Symptom, Cost & Fixes - TruckGuider
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.