P2ADE: Reductant Tank Temperature Sensor B Circuit

P2ADE is the general circuit code for reductant tank temperature sensor B, intended for systems that report a fault on this input without splitting it into low, high or erratic. No manufacturer documents P2ADE publicly. GM, where the sensor B family is on record, reports such faults through P2ADB, P2ADC and P2ADD plus the plausibility code P2ADA, and its 2025 DEF controller names exactly those four as the sensor B fault set. Deutz files an open circuit of its second tank temperature sensor at the suction point under its own code P1241 instead. CARB requires emission-related inputs to be checked for open circuits and for readings outside their possible range. Where P2ADE does show up, treat it as an open or unreadable sensor B circuit: inspect connector, wiring and the tank sensor unit.

Symptoms

• Check engine light on
• DEF or SCR warning
• Possible inducement countdown

Most likely causes

• Open signal line or unplugged tank sensor connector
• Failed tank sensor unit
• Input fault in the SCR or engine control module

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the AdBlue/DEF level and quality, and do not add additives or water
2. Look for white crystals around the injector and the tank
3. Check connectors and heaters with the scanner
4. Run the dosing test available on your diagnostic tool
5. Replace parts only when the test points to that component

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P2ADE means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• A: Hybrid or air and fuel
• DE: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2ADE?

Deal with it soon. If the instrument cluster shows a countdown, the car may not restart once it reaches zero.

What causes code P2ADE?

The most common causes are: open signal line or unplugged tank sensor connector; failed tank sensor unit; input fault in the SCR or engine control module.

Related codes

• P2ADAReductant Tank Temperature Sensor B Circuit Range/Performance
• P2ADBReductant Tank Temperature Sensor B Circuit Low
• P2ADCReductant Tank Temperature Sensor B Circuit High
• P2ADDReductant Tank Temperature Sensor B Circuit Intermittent/Erratic
• P205AReductant Tank Temperature Sensor A Circuit

Sources

• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 25OBDG04A
• serdia.deutz.com: DTCList EMRL1 MainECU EN

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.