Faulty temperature sensor 1 on hydrogen tank C; Damaged or corroded wiring or connector at the sensor; Open or short circuit in the sensor signal or ground circuit; Poor electrical connection at the powertrain control module; Failed powertrain control module (rare); Mechanical damage to the sensor or its mounting; Extreme environmental conditions causing sensor malfunction

DTC codes / U35xx · Network communication / U354E

U354EHydrogen Tank C Temperature Sensor 1 Circuit

Q: What does code U354E mean?

Hydrogen Tank C Temperature Sensor 1 Circuit. This code indicates that the powertrain control module has detected an abnormal condition in the temperature sensor circuit for hydrogen tank C, specifically sensor 1. The computer monitors the sensor's signal voltage and flags a fault when the reading falls outside the expected range for the current operating conditions, which can affect how the system manages the tank's temperature.

This code indicates that the powertrain control module has detected an abnormal condition in the temperature sensor circuit for hydrogen tank C, specifically sensor 1. The computer monitors the sensor's signal voltage and flags a fault when the reading falls outside the expected range for the current operating conditions, which can affect how the system manages the tank's temperature.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaNetwork communication

Symptoms you may notice

Illumination of the malfunction indicator lamp on the dashboard
Often no symptoms besides the warning light
Reduced power or limited operation if the system enters a protective mode
Inaccurate or unavailable temperature readings for the hydrogen tank
Possible inability to refuel or complete a refueling event
Other warning messages related to the hydrogen system

Common causes, most likely first

Faulty temperature sensor 1 on hydrogen tank C
Damaged or corroded wiring or connector at the sensor
Open or short circuit in the sensor signal or ground circuit
Poor electrical connection at the powertrain control module
Failed powertrain control module (rare)
Mechanical damage to the sensor or its mounting
Extreme environmental conditions causing sensor malfunction

How to diagnose and fix it

Perform a visual inspection of the sensor, wiring, and connectors for obvious damage or corrosion
Use a scan tool to read live data and compare the sensor reading with a known good value or ambient temperature
Check the sensor's resistance or voltage output according to the manufacturer's specifications
Test the continuity and resistance of the signal and ground circuits between the sensor and the control module
Inspect and clean the connector terminals, then apply dielectric grease if recommended
Replace the temperature sensor if it fails electrical testing
Clear the diagnostic trouble codes and verify the repair by test-driving the vehicle and monitoring the sensor data

Hydrogen tank sensor diagnostics you should not overlook

A common mistake is replacing the sensor without first checking the wiring harness for chafing or loose pins, which can mimic a sensor failure.
The code can set intermittently due to vibration or thermal cycling, so a wiggle test of the harness while monitoring live data is often revealing.
On some vehicles, a low coolant level or air pockets in the tank cooling system can cause temperature readings to go out of range and set this code.
The powertrain control module may use this sensor signal for refueling control, so a fault can prevent the tank from accepting fuel even if the sensor appears to work otherwise.
Always verify that the replacement sensor is compatible with the hydrogen system and that the system is depressurized before servicing any component.

Can I keep driving with U354E?

It is generally safe to continue driving with this code if the vehicle operates normally, but avoid aggressive driving or refueling until the fault is repaired. If the vehicle enters a reduced power mode or shows other warning lights, seek service promptly.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.