|
No.
|
TECH 1 Display
|
Conditions for Checking
|
Nominal Value
|
Trouble Codes
|
Terminal
|
|
29
|
AIR/FUEL RATIO
|
Engine running at idle speed, operating temperature
|
alternating
LEAN
and
RICH
|
13, 44, 45
|
-
|
|
|
|
|
|
|
|
|
Notes on
Trouble-shooting:
|
Nominal
Value:
|
Cause of
fault:
(If nominal
value is not attained)
|
|
· AIR/FUEL RATIO is an internal value
of the engine control unit and is dependent on the oxygen sensor signal
TECH 1 data list no. 27 O2
SENSOR, which is received by the engine control unit.
|
|
· Engine running
at idle speed, operating temperature
· TECH 1
data list no. 29 AIR/FUEL RATIO
|
alternating, approx. 1 to 5 times per second
LEAN
RICH
|
Alternates faster:
· Oxygen sensor
loose
· Misfiring in
one cylinder
Alternates very slowly:
· Oxygen sensor
defective due to tetraethyl lead
· Outside of
oxygen sensor dirtied with silicone / fuel / underseal.
|
|
· Check the
following nominal values:
|
|
|
|
· TECH 1
data list no. 27
O2 SENSOR
· TECH 1
data list no. 28
O2 SENSOR LOOP
· TECH 1
data list no. 30
O2 INTEGRATOR
· TECH 1
data list no. 31
O2 BLM ENABLE
· TECH 1
data list no. 32
O2
BLM CELL NO.
TECH 1 data list no. 33
O2
BLM CELL CONT
|
OK
OK
OK
OK
OK
OK
|
· Remedy
according to data list no. 27
O2 SENSOR
· Remedy
according to data list no. 28
O2 SENSOR LOOP
· Remedy
according to data list no. 30
O2 INTEGRATOR
· Remedy
according to data list no. 31
O2 BLM ENABLE
· Remedy
according to data list no. 32
O2
BLM CELL NO.
· Remedy
according to data list no. 33
O2
BLM CELL CONT
|
|
· Ignition OFF
· Disconnect
wiring harness plug from:
K57 engine control unit
· Check control
unit calibration, see field remedy measures
|
Latest program memory (EPROM) according to field remedy
measures or TIs
|
· Replace program
memory (EPROM) according to field remedy measures or TIs
|
|
|
If nominal values are attained and the latest program memory is
installed
|
· K57 engine
control unit defective
|
|
|
|
|
|
|
|
|
|
|
|
|
