Retarder (RET) diagnosis, troubleshooting · ad4340l5000a · Mercedes-Benz WIS

AD43.40-L-5000A

Retarder (RET) diagnosis, troubleshooting

20.1.98

MODELS 668.323 /353, 670.323 /324 /353 /373 /374 with ENGINES 904.908 /914 /923 /936
with CODE (B02) Brake system, antilock brake system (ABS)
with CODE (B16) 2-circuit hydraulic brake/2-circuit compressed air brake
with CODE (BR3) CC 80 retarder
with CODE (BR5) Combined manual and foot-operated switch for retarder

	Retarder (RET) diagnosis, previous knowledge		AD43.40-L-2000A
	Retarder, electric, location of components		GF43.40-L-0001-01A
	Troubleshooting
Complaint	possible cause	Note	Remedy
No braking effect	 Ground cable at retarder reactor (M36) loose  Positive battery cable of battery to relay box (A15) loose  Connecting cable from relay box (A15) to retarder reactor (M36) loose or damaged  Current supply to retarder manual selector (S150) interrupted  Cable from retarder manual selector (S150) to relay box (A15) faulty		Inspect cables, plugs and connectors for damage, correct connection, loose contact, corrosion, etc., replace if necessary.
	 Retarder manual selector (S150) faulty	up to 30.6.99	AD43.40-L-6000-01A
	 Retarder switch (S201.2s2) faulty	as of 01.07.99	AD43.40-L-6000-01B
	 Connection from ABS to ABS retarder interface (A23) interrupted		AD43.40-L-6000-05A
One or more stages without function (inadequate braking effect)	 Connecting cable from relay box (A15) to retarder reactor (M36) loose or damaged  Cable from retarder manual selector (S150) to relay box (A15) faulty  Cable from retarder selector (S201.2s20) to relay box (A15) faulty	up to 30.6.99 as of 01.07.99	Inspect cables, plugs and connectors for damage, correct connection, loose contact, corrosion, etc., replace if necessary.
	 Relay in relay box (A15) faulty		Test relay, replace if necessary
	 Melting fuse in relay box (A15) blown		Replace fuse, eliminate any short circuit
	 Retarder manual selector (S150) faulty	up to 30.6.99	AD43.40-L-6000-01A
	 Retarder switch (S201.2s2) faulty	as of 01.07.99	AD43.40-L-6000-01B
	 One or more coils in a circuit (stage) faulty		AD43.40-L-6000-04A
Retarder indicator (H94) illuminated, although the retarder manual selector (S150) or retarder switch (S201.2s2) is located in position "0"	 Retarder manual selector (S150) faulty  Retarder switch (S201.2s2) faulty	up to 30.6.99 as of 01.07.99	AD43.40-L-6000-01A AD43.40-L-6000-01B
	 Relay in relay box (A15) faulty		Check relay in relay box (A15), replace if necessary
Foot control without function	 Retarder isolating switch (S152) for foot switching actuated or faulty		AD43.40-L-6000-02A
	 Ground connection at retarder pressure switching unit (B88) interrupted		AD43.40-L-6000-03A
	 Speedometer signal disrupted		Check C3 connection at tachograph
	 Connection from ABS to ABS retarder interface (A23) interrupted		AD43.40-L-6000-05A
	 ABS without function	Check ABS	AD42.30-L-1000AZ
	 Telma ABS interface (A23) faulty		Replace Telma ABS interface (A23)
Retarder (M36) switches on automatically, retarder indicator (H94) not illuminated	 Retarder manual selector (S150) faulty	up to 30.6.99	AD43.40-L-6000-01A
	 Retarder switch (S201.2s2) faulty	as of 01.07.99	AD43.40-L-6000-01B
	 Retarder indicator (H49) connected incorrectly or faulty		Check retarder indicator (H49), replace if necessary
Retarder (M36) switches on automatically or remains switched on after pressing the service brake, retarder indicator (H94) illuminated	 Relay in relay box (A15) faulty		Check relay in relay box (A15), replace if necessary
	 Retarder manual selector (S150) faulty	up to 30.6.99	AD43.40-L-6000-01A
	 Retarder switch (S201.2s2) faulty	as of 01.07.99	AD43.40-L-6000-01B
	 Pressure switch in pressure switching unit (B88) faulty		AD43.40-L-6000-03A
Severe arcing at the relay contacts, contacts charred	 Ground connection for relay box too small or inadequately mounted		Connect circuit M of relay box (A15) to at least 10 mm2 cable and good vehicle ground
	 Overrunning diode in relay box (A15) faulty	Diodes are located on the rear side of the relay box base	Replace diodes
Relay in relay box (A15) remains dangling	 Retarder manual selector (S150) faulty	up to 30.6.99	AD43.40-L-6000-01A
	 Retarder switch (S201.2s2) faulty	as of 01.07.99	AD43.40-L-6000-01B
	 Ground connection for relay box too small or inadequately mounted		Connect circuit M of relay box (A15) to at least 10 mm2 cable and good vehicle mass

Referenced documents

ad4230l1000az Anti-lock brake system (ABS) diagnosis contents
ad4340l2000a Retarder (RET) diagnosis, previous knowledge
ad4340l600001a Retarder manual selector - RET electrical system test
ad4340l600001b Retarder manual selector - RET electrical system test
ad4340l600002a Retarder circuit breaker, testing electrical system of RET
ad4340l600003a Retarder pressure switch unit, testing electrical system of RET
ad4340l600004a Retarder power consumption, testing electrical system of RET
ad4340l600005a Retarder ABS relay, testing electrical system of RET
gf4340l000101a Retarder, electric, location of components