|
No.
|
TECH 1 Display
|
Conditions for
Checking
|
Nominal Value
|
Trouble Codes
|
Terminal
|
|
19
|
COOLANT TEMP.SW.
|
Automatic transmission AF
14/20 with installed coolant temperature switch, connected to Ter. 11 of
transmission control unit (Model Year '89 with EI Plus engine control units)
Ignition ON
Engine cold
Apply parking brake
Selector lever in "P"
or "N"
Engine running at idle speed,
operating temperature
Coolant temperature higher than
75 °C/167 °F
Automatic transmission AF
13/14/20 without installed coolant temperature switch
(control unit Ter. 11
grounded, Ter. 31)
Ignition ON
|
OPEN 12V
CLOSED 0V
|
15, 23
|
11, 35
|
|
|
|
Note:
In the AF 22 automatic
transmission, the control unit Ter. 11 is not connected to the coolant
temperature switch. Ter. 11 of the transmission control unit is connected to
Ter. 42 of the Motronic control unit (C 25 XE engine with Motronic M 2.8).
This lead transfers information about the P/N switch position to the Motronic
control unit. See test step 28. TECH 1 displays "NOT USED" for the
presently selected parameter.
|
CLOSED 0V
|
|
|
|
Trouble-shooting:
|
Nominal Value:
|
Cause of
Fault:
(If nominal
value is not attained)
|
|
EI + only:
|
|
|
|
· Ignition OFF
· Disconnect coolant
temperature switch wiring harness plug S 115
· Ignition ON
|
|
|
|
· Using TECH 1, select test
step no. 19
|
OPEN 12V
|
· Short circuit to ground
from: transmission control unit wiring harness plug Ter. 11
to: Coolant temperature switch wiring harness plug S 115
Ter. 1
· Transmission control unit
defective.
|
|
· Connect coolant temperature switch
wiring harness plug S 115 Ter. 1 to ground
· Using TECH 1, select test step no. 19
|
CLOSED 0V
|
· Circuit interruption
from: transmission
control unit wiring harness plug Ter. 11
to: Coolant
temperature switch wiring harness plug S 115 Ter. 1
· Short circuit to voltage
from: transmission
control unit wiring harness plug Ter. 11
to: Coolant
temperature switch wiring harness plug S 115 Ter. 1
· Transmission control unit defective.
|
|
· Connect coolant
temperature switch wiring harness plug S 115 Ter. 1 with Ter. 2
|
CLOSED 0V
|
· Circuit interruption
from: Coolant temperature switch wiring harness plug S 115 Ter.
2
to: ground, Ter. 31
· Short circuit to voltage
from: Coolant temperature switch wiring harness plug S 115 Ter.
2
to: ground, Ter. 31
|
|
|
If nominal values are attained
|
· Coolant temperature
switch S 115 defective
|
|
|
|
|
|
|
|
|
