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Diagnostic Manual, Engines, Volume 3

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LOCATION:    7.1 Cruise Control/Idle Speed Control (CC/ISC)   >   11 Diagnosis - Diagnostic Trouble Code (DTC) Readout

Diagnosis - Diagnostic Trouble Code (DTC) Readout

Preparation for DTC Readout

Connect impulse counter scan tool and/or HHT to data link connector (X11/4) according to connection diagram (see section 0).
yellow wire to socket 7


Hand-Held Tester (HHT) 1) see current MBUSA service information in groups 58 and 99
1) Available through the MBUSA Standard Equipment Program.

Diagnostic trouble code (DTC) Possible cause Test step/Remedy 1)
No fault in system -

CC/ISC control module (N4/3)
Safety contact switch (M16/3s1)
Stop lamp switch (S9/1)
Cruise control switch (S40) OFF
CC/ISC control module (N4/3)
Actual value potentiometer (M16/1r2)
Starter lock-out/back-up lamp switch (S16/3) (transmission range recognition)
Engine speed (TNA) signal
Vehicle speed signal (VSS)
Safety relay within CC/ISC control module (N4/3)
CC/ISC control module (N4/3)
Engine harness
23 6.0 -8.0
23 17.0
23 2.0
23 3.0 , 5.0
23 11.0
23 14.0
23 15.0 , 16.0
Check harness wire insulation.
Conditions for activation of CC/ISC actuator (M16/2) not fulfilled. Conditions:
Engine: OFF
Transmission range: P/N

CC/ISC actuator (M16/2)
Throttle valve actual valve potentiometer (M16/2r2)
Drive actual value potentiometer (M16/2r1)
Safety contact switch (M16/2s1)
Closed throttle recognition switch (M16/2s2)
CC/ISC actuator (M16/2) (voltage supply)
Reset not accomplished (actuator adaptation)
23 3.0 -10.0
23 5.0
23 4.0
23 6.0 , 8.0
23 6.0 , 7.0
23 3.0
Erase DTC:
Ignition: OFF
Ignition: ON (for at least 90 seconds).
If DTC reappears:
CC/ISC actuator (M16/2)
Cruise control switch (S40) 23 2.0
Stop lamp switch (S9/1) 23 17.0
Not valid for U.S.A. vehicles  

CAN databus:
Message from CC/ISC control module (N4/3) faulty
Reception from LH-SFI control module (N3/1) faulty
23 21.0
Left front axle vehicle speed signal (L6/1) from ABS control module (N30) 23 15.0
Rear axle vehicle speed signal (L6) from ABS control module (N30) 23 16.0
Engine speed signal (TNA) from base module (N16/1) 23 14.0

Fuel safety shut-off signal to LH-SFI control module (N3/1)
Closed throttle recognition signal to LH-SFI control module (N3/1)
23 19.0
23 20.0
Voltage supply, circuit 87 23 1.0
1) Observe Preparation for Test, see 22 .