2003 MERCEDES-BENZ E320 4MATIC WAGON engine

244 Malfunction and indicator lamps
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
Malfunction and indicator lamps
in the instrument cluster
General information:
If a bulb in the instrument cluster fails to light up
during the bulb self-check when turning the electronic
key in steering lock to position 2, have it checked and
replaced if necessary.
On-board diagnostic system
Check engine malfunction indicator lamp
Engine malfunction indicator lamp. If the
“CHECK ENGINE” malfunction indicator
lamp comes on when the engine is running,
it indicates a malfunction of the fuel management
system, emission control system, systems which impact
emissions, or the fuel cap is not closed tight (check the
fuel cap). If the “CHECK ENGINE” lamp is illuminated
continuously and the vehicle is driving normally, you
may still drive the vehicle, however, in all cases, we
recommend that you have the system checked at your
authorized Mercedes-Benz Center as soon as possible. If the “CHECK ENGINE” lamp comes on continuously
and / or the vehicle is not driving normally, serious
damage can occur to the emission system. Please
contact your authorized Mercedes-Benz Center
immediately.
The Sequential Multiport Fuel Injection (SFI) control
module monitors emission control components that
either provide input signals to or receive output signals
from the control module. Malfunctions resulting from
interruptions or failure of any of these components are
indicated by the “CHECK ENGINE” malfunction
indicator lamp in the instrument cluster and are
simultaneously stored in the SFI control module.
If the “CHECK ENGINE” malfunction indicator lamp
comes on, have the system checked at your authorized
Mercedes-Benz Center as soon as possible.
With some exceptions, the control module switches off
the “CHECK ENGINE” malfunction indicator lamp if the
condition, causing the lamp to come on, no longer exists
during three consecutive cycles. See also page 246 for
fuel cap placement warning.
CHECK
ENGINE

245 Malfunction and indicator lamps
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index An on-board diagnostic connector is located in the
passenger compartment near to the parking brake
pedal, allowing the accurate identification of system
malfunctions through the readout of diagnostic trouble
codes.
Brake warning lamp
Except Canada
Canada only
When the brake warning lamp and message appear
while the engine is running, this means:
•there is insufficient brake fluid in the reservoir
(engine running and parking brake released), or
•the parking brake is set (engine running).Note:
If you find that the brake fluid in the brake fluid
reservoir has fallen to the minimum mark or below,
have the brake system checked for brake pad thickness
and leaks.
BRAKE
Wa r n i n g !
Driving with the brake warning lamp illuminated
can result in an accident. Have your brake system
checked immediately if the brake warning lamp
stays on. Don’t add brake fluid before checking the
brake system. Overfilling the brake fluid reservoir
can result in spilling brake fluid on hot engine
parts and the brake fluid catching fire. You can be
seriously burned.

246 Malfunction and indicator lamps
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
Supplemental restraint system (SRS) indicator lamp
The operational readiness of the airbag
system is verified by the indicator lamp SRS
in the instrument cluster when turning the
electronic key in steering lock to position 1 or 2. If no
malfunction is detected, the lamp will go out after
approximately 4 seconds; after the lamp goes out, the
system continues to monitor the components and
circuitry of the airbag system and will indicate a
malfunction by coming on again.
See page 68 for notes on airbags, see page 67 for belt
tensioners and page 57 for infant and child seat
restraint.Fuel reserve and fuel cap placement warning
When the warning lamp (1) comes on after starting the
engine, or if it comes on while driving, it indicates that
the fuel level is down to the reserve quantity of
approximately 2.6 gal (10 liters).
The warning lamp blinks when the fuel cap is not
closed, or a fuel system leak has been detected.
Retighten cap and see if lamp goes out after restart and
next OBD selfcheck.
If the warning lamp continues to blink after closing the
fuel cap correctly, have the fuel system checked at your
authorized Mercedes-Benz Center as soon as possible.
Leaving the engine running and the fuel cap open can
also cause the “CHECK ENGINE” lamp to illuminate, see
also page 244.
Wa r n i n g !
In the event a malfunction of the SRS is indicated
as outlined above, the SRS may not be operational.
For your safety, we strongly recommend that you
visit an authorized Mercedes-Benz Center
immediately to have the system checked; otherwise
the SRS may not be activated when needed in an
accident, which could result in serious or fatal
injury, or it might deploy unexpectedly and
unnecessarily which could also result in injury.SRS
1
P54.30-4557-21

247 Malfunction and indicator lamps
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index Electronic stability program (ESP) — warning lamp
The yellow ESP warning lamp in the
speedometer dial comes on with the
electronic key in steering lock position 2. It
should go out with engine running.
See page 229 and 230 if the warning lamp lights up or
flashes when the vehicle is moving.BAS / ESP malfunction indicator lamp
The malfunction indicator lamp for the ESP
is combined with that of the BAS.
The yellow BAS / ESP malfunction indicator
lamp in the instrument cluster comes on with the
electronic key in steering lock position 2. It should go
out with the engine running.
If the BAS / ESP malfunction indicator lamp remains
illuminated with the engine running, see page 225 for
notes on brake assist system (BAS) and page 230 for
notes on electronic stability program (ESP).

248 Malfunction and indicator lamps
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
ABS malfunction indicator lamp
The ABS malfunction indicator lamp in the
instrument cluster comes on with the
electronic key in steering lock position 2 and
should go out with the engine running.
When the ABS malfunction indicator lamp symbol and
warning in the instrument cluster remains illuminated
while the engine is running, it indicates that the ABS
has detected a malfunction and has switched off. In this
case, the brake system functions in the usual manner,
but without antilock assistance.
With the ABS malfunctioning, the BAS and ESP are also
switched off. Both malfunction indicator lamps come on
with the engine running.If the charging voltage falls below 10 volts, the
malfunction indicator lamp comes on and the ABS is
switched off. When the voltage is above this value again,
the malfunction indicator lamp should go out and the
ABS is operational.
Have the system checked at your authorized
Mercedes-Benz Center as soon as possible.
See page 227 for notes on antilock brake system (ABS).
Seat belt warning lamp
With the electronic key in steering lock
position 2, the seat belt warning lamp comes
on and a warning sounds for approximately
6 seconds if the driver’s seat belt is not fastened.
ABS

251 Malfunction and warning messages
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index DISPLAY DEFECTIVE (engine control unit)
This message is displayed to indicate that the
information being relayed by the engine control unit is
no longer complete. The coolant temperature gauge,
tachometer, or the cruise control may have failed.DISPLAY DEFECTIVE (several systems)
The displays for several systems have failed. Some
systems themselves may also have failed.
Line 1 Line 2
DISPLAY DEFECTIVE VISIT WORKSHOP!
Line 1 Line 2
DISPLAY DEFECTIVE VISIT WORKSHOP!

252 Malfunction and warning messages
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
BATTERY / ALTERNATORThis message indicates a malfunction which must be
repaired immediately.
It may indicate that the poly-V-belt has broken. Should
this condition occur, the poly-V-belt must be replaced
before continuing to operate the vehicle. Otherwise, the
engine will overheat due to an inoperative water pump
which may result in damage to the engine.
Do not continue to drive the vehicle with this message
displayed.
Doing so could result in serious engine damage that is
not covered by the Mercedes-Benz Limited Warranty.
Line 1 Line 2
BATTERY / ALTERNATOR VISIT WORKSHOP!
OVERVOLTAGE VISIT WORKSHOP!
UNDERVOLTAGE CONSUMER DEFECTIVE!

254 Malfunction and warning messages
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
BRAKE LINING WEAR
When this message appears during braking, it indicates
that the brake pads are worn down.
Have the brake system checked at your authorized
Mercedes-Benz Center as soon as possible.
Brake pad thickness must be visually checked by a
qualified technician at the intervals specified in the
service booklet. BRAKE FLUID
Line 1 Line 2
BRAKE LINING WEAR VISIT WORKSHOP!
Line 1 Line 2
BRAKE FLUID VISIT WORKSHOP!Wa r n i n g !
Driving with this message displayed can result in
an accident. Have your brake system checked
immediately. Don’t add brake fluid before checking
the brake system. Overfilling the brake fluid
reservoir can result in spilling brake fluid on hot
engine parts and the brake fluid catching fire. You
can be seriously burned.