Check hydrogen sensors of tank system for proper operation and soiling

AP06.40-P-0650FC

Check hydrogen sensors of tank system for proper operation and soiling

15.11.2019

Model

253.99

1

Hydrogen sensor 1 on the fuel tank over the rear axle

 Danger

Risk of explosion when using a forming gas with incorrect mixing ratio. Risk of suffocation due to inhalation of forming gas. Risk of injury due to bursting of high-pressure hoses.

Wear safety glasses and protective gloves. No smoking or open flames. Work in well-ventilated rooms only.

AS83.00-Z-0001-02A

 Danger

Risk of death when working on component parts and systems with U >= 30 V alternating voltage (AC) or U >= 60 V direct voltage (DC)

Do not touch damaged or defective live component parts and lines or non-insulated electrical connections and lines.

AS00.00-Z-0035-01A

 Danger

Risk of explosion caused by escaping hydrogen or overheating of the fuel tanks when working on the hydrogen system. Risk of frostbite to body parts caused by escaping gas and by touching component parts carrying gas when emptying fuel tanks. Risk of asphyxiation caused by inhalation of air diluted by hydrogen. Risk of burn injuries by coming into contact with an invisible pale blue hydrogen flame.

AS00.00-Z-0030-01B

Topical note

Notes on fuel cell system

AH00.00-P-0022-01RFW

Topical note

General information on handling vehicles with high-voltage on-board electrical system and/or lithium-ion battery and/or gaseous-fuel drive system

AH00.00-Z-0300-01A

Preparatory activity

1

Connect charger for receiving on-board electrical system voltage to vehicle.



AR54.10-P-1127LW

2

Connect diagnostic system.



AD00.00-P-2000-04B



Remove

3

Remove underfloor paneling over hydrogen sensor 1 on the fuel tank over the rear axle (1).



AR61.30-P-1001RFW

 Dismantling tool

*000589956300



Check

4

Check hydrogen sensor 1 on the fuel tank over the rear axle (1) for soiling and damage.

 If necessary, use commercially available devices/tools. Explosion-proof flashlight, comparable to AccuLux flashlight MHL 5 EX from Witte + Sutor GmbH.

 If necessary, use commercially available devices/tools. Swiveling inspection mirror.

If there is damage at hydrogen sensor 1 on the fuel tank over the rear axle (1) or fouling in the area of the sensor opening,



replace hydrogen sensor 1 on the fuel tank over the rear axle (1).



Model 253.992/993 with engine 780

AR47.50-P-0001RFW

 After obtaining special order.

5

Check hydrogen sensor 1 on the fuel tank over the rear axle (1) using vehicle diagnosis system.



253 588 00 21 00 Test equipment

WS47.00-P-0044B



000 588 19 21 00 Leak tester

WS83.00-P-0035B


The forming gas must flow directly to the sensor opening of the hydrogen sensor 1 on the fuel tank over the rear axle (1).
Otherwise, incorrect measurement values are shown.

 In accordance with the instructions in the diagnostic system, use the test equipment to apply forming gas (95 % nitrogen, 5 % hydrogen) to the hydrogen sensor 1 on the fuel tank over the rear axle (1).

If detection on the hydrogen sensor 1 on the fuel tank over the rear axle (1) is within its limits,



hydrogen sensor 1 on the fuel tank over the rear axle (1) is OK.

If detection in hydrogen sensor 1 on the fuel tank over the rear axle (1) is not within its limits,



replace hydrogen sensor 1 on the fuel tank over the rear axle (1).



Model 253.992/993 with engine 780

AR47.50-P-0001RFW

 After obtaining special order.



Install

6

Install underfloor paneling over hydrogen sensor 1 on the fuel tank over the rear axle (1).



AR61.30-P-1001RFW

Finishing activity

7

Disconnect diagnostic system.



AD00.00-P-2000-04B

8

Disconnect charger for receiving on-board electrical system voltage at vehicle.



AR54.10-P-1127LW