Service Bulletin
Volvo Trucks North America, Inc.
Greensboro, NC USA Trucks
Date Group No. Page
11.2002 275 13 1(12)
Cruise Control
Fault Tracing
Checklist K
D12D
Cruise Control, Fault Tracing
Checklist K
T2018950
This information covers fault tracing the cruise control function of the Volvo D12D en-
gine.
Contents
General Guide to Fault Tracing page 2
Overview of Cruise Control, Volvo Engine page 3
Checklist K, Cruise Control page 5
Cruise Control, Fault Tracing page 7
NOTE: Information is subject to change without notice.
Illustrations are used for reference only, and may differ slightly from the actual
engine version. However, key components addressed in this information are repre-
sented as accurately as possible.
PV776-TSP170585 USA11315
Page 2
General Guide to Fault Tracing
(See also Cruise Control, Fault Tracing page 1.)
You must read and understand the precautions and guidelines in Service Informa-
tion, group 20, "General Safety Practices, Engine" before performing any procedure.
If you are not properly trained and certified in a procedure, ask your supervisor for
training before you perform it.
To use this checklist:
1 Complete basic data gathering
Read fault codes
Check vehicle parameters
2 Use the recommendations in appropriate symptom information, plus the infor-
mation gathered above to provide a foundation for continued fault tracing using
this checklist.
One fault often affects other systems. Therefore, it is important to confirm or
eliminate suspected causes of faults at an early stage, using tests in VCADS
Pro.
Volvo Trucks North America, Inc. Date Group No. Page
Service Bulletin 11.2002 275 13 3(12)
Overview of Cruise Control, Volvo Engine
W2003971
It is important to understand the function of the system when fault tracing. Fol-
low the fault tracing sequence in the checklist to avoid possible replacement of
non-defective components.
Page 4
Operation Brake Test
Cruise control is activated by positioning the switch on For cruise control to be activated, a brake test must first
the cruise controller (S25) in the ON position and by be approved by depressing the brake pedal for approxi-
pressing SET +/ at a set speed. The VECU (A17) de- mately 2 seconds.
tects the controller signal and forwards them to the
engine control unit (A14). When the brake lamp is activated by the pressure switch
(S48), a signal is transmitted from the pressure switch
Pressing SET + increases speed; SET reduces speed. via the lamp control unit (LCM) (A27) the exterior
lighting control unit to the VECU (A17), which also re-
When SET +/ is released, the vehicle speed is pro- ceives a signal from the brake pedal switch (S59).
grammed into the VECU (A17), provided that the speed
is within the cruise control speed interval. Parameters Both the signals must be active in order for the brake
BK and AI determine the minimum speed and maximum test to be approved. The VECU stores the fact that the
speed of the cruise control. brake test has been approved in the memory. It is now
possible to activate cruise control.
The vehicle speed sensor (B68) transmits information
about the speed to the VECU (A17) which compares this
with the set speed.
The cruise control is disengaged when the brake pedal
(S59) or the clutch pedal (S58) are depressed. The pre-
vious set speed is stored in VECU memory.
When the cruise control switch is in the RESUME posi-
tion, the vehicle will return to the previously stored
speed. Cruise control can also be completely disen-
gaged by moving the switch to the OFF position.
Volvo Trucks North America, Inc. Date Group No. Page
Service Bulletin 11.2002 275 13 5(12)
Checklist K, Cruise Control
See also:
General Guide to Fault Tracing page 2
Cruise Control, Fault Tracing page 7
Vehicle Chassis No. Mileage Customer
Yes No
1 Fault Codes, Checking page 7
Have the fault codes relating to cruise control been corrected?
Action:
2 Calibration-number (K), Checking page 7
Calibration Number (K) VECU
Is the calibration number correctly programmed?
Action:
3a Cruise Control Function Test page 8
Signal checks
Does the indicating lamp light up when switches are activated?
Voltage supply switch, cruise control
Voltage supply, pedal switches
Status, cruise control, ON
Status cruise control, RESUME
Status cruise control, SET+/-
Does the indicating lamp for SET + light up after 1 second?
Does the indicating lamp for SET - light up after 1 second?
Does the indicator lamp only light up when the pedal is depressed?
Status pedal switch, clutch
Status pedal switch, brakes
Status pressure switch, brake lamp
Has the brake test been approved?
Speed settings
Max speed km/h (mph)
Min speed km/h (mph)
Are the setting values within their permitted range?
Page 6
Vehicle Chassis No. Mileage Customer
Yes No
3b Test driving
Speed checks
Set Speed km/h (mph)
Actual speed km/h (mph)
Does set speed indicated correspond to actual speed?
Signal checks
Does the indicating lamp light up when cruise control is active?
Status cruise control, active
Action
Notes:
Completed by: Dealer: Date:
Volvo Trucks North America, Inc. Date Group No. Page
Service Bulletin 11.2002 275 13 7(12)
2751-20-03-01
Cruise Control, Fault Tracing
See also:
General Guide to Fault Tracing page 2
Checklist K, Cruise Control page 5
Fault Codes, Checking
Correct any fault codes relating to Cruise Control before
beginning fault tracing. The following fault codes can af-
fect Cruise Control function:
MID 128 PID 84 FMI 9, 11 Vehicle speed
MID 128 PID 85 FMI 9 Cruise control, status switch
MID 128 PID 228 FMI 11 Calibration number (K)
MID 144 PID 84 FMI 2, 5, 8, 13 Vehicle speed
MID 144 PPID 70 FMI 4 Pedal switches
MID 144 PPID 76 FMI 3, 4 Brake lamp, status relay
MID 144 PPID 84 FMI 2, 3, 4, 5, 8, 13 Speed signal, status
MID 144 SID 243 FMI 7 Cruise control switch SET
MID 144 PSID 1 FMI 7 Solenoid valve
Calibration-number (K), Checking
1
Using the PC tool, check that the cali-
bration number (K) is correctly set in
the VECU. Also check that the EECU
correctly reads the calibration number
(K) for the VECU.
2
Check that the correct calibration num-
ber (K) is programmed (parameter ID:
MH).
Page 8
Cruise Control Function Test Voltage power supply, pedal switches
Connect the PC tool to the vehicles diagnostics connec-
tor. Perform Cruise control function, test; follow 2
instructions in VCADS Pro.
Special tools: 9813194, 9990014, 9990025,
9998533, 9998699, 85104406, 85104407,
85104410
Other special equipment: J-39200
Explanations of results when test-
ing
T2012907
Check that the indicator lamp in the
test lights up when the test has
started.
T2012904
1 Active signal. 3
2 Inactive signal. If the lamp does not light up, there is
3 Fault in the reading. no voltage available for the pedal
Restart the test and try again. switches and the cruise control func-
Check the terminals for the diagnostic socket. tion will not work.
Check the fault codes.
4 The signal is not available.
Fault code: MID 144, PPID 70, FMI 4.
The function is not available on the vehicle.
Fault-trace using fault code informa-
tion, group 36.
Signal Checks
Status, cruise control, ON
Voltage supply switch, cruise control
1 4
T2012906
Check that the indicator lamp lights up
once the test has started. T2012908
If the lamp does not light up there is Check that the indicator lamp in the
no voltage to the control. test lights up when the switch is set to
Fault-trace using the wiring diagram. the ON position .
Volvo Trucks North America, Inc. Date Group No. Page
Service Bulletin 11.2002 275 13 9(12)
5 Status cruise control, SET+/-
If the lamp does not light up, check the
connector at the control as well as at 10
the VECU. Also check that the wires
are in good condition.
6
If the connector and wires are in good
condition, the fault is in the switch.
See wiring diagram.
Status cruise control, RESUME
T2012909
Check that the indicator lamp for SET
+/ lights up in the test when SET +
and SET are held down. After ap-
proximately 1 second the indicator
lamp should also light up.
11
If the lamp does not light up on both
SET + and SET , check the connec-
T2012910
tor at the control as well as at the
Check that the indicator lamp in the VECU. Also check that the wires are in
test lights up when the switch is set to good condition.
the RESUME position.
12
8 If the connector and wires are in good
If the lamp does not light up, check the condition, the fault is in the switch.
connector at the control as well as at See wiring diagram.
the VECU. Also check that the wires
are in good condition.
Status cruise control, SET (coast)
9 13
If the connector and wires are in good Check that the indicator lamp for SET
condition, the fault is in the switch. lights up in the test approximately 1
See wiring diagram. second after the SET button is held
down.
14
If the lamp does not light up, check the
connector at the control as well as at
the VECU. Also check that the wires
are in good condition.
15
If the connector and wires are in good
condition, the fault is in the switch.
See wiring diagram.
Page 10
Status cruise control, SET + (acceleration) 21
Connect breakout harness 9813194
16 and breakout box 9998699 (use over-
Check that the indicator lamp for SET lay 85104407) between PA connector
+ lights up in the test approximately 1 and VECU.
second after the SET + button is held
down.
22
With ignition key in ON position, check
17 voltage at VECU.
If the lamp does not light up, check the
connector at the control as well as at
Measurement Expected value
the VECU. Also check that the wires
point
are in good condition.
PA8 (signal) - B+ V (pedal at
PA12 (ground) rest; switch
18
closed)
If the connector and wires are in good
0 V (pedal de-
condition, the fault is in the switch.
pressed; switch
See wiring diagram.
open)
Status pedal switch, clutch
NOTE: When pedal is at rest, switch
19 closed, B+ should be at PA8, and indi-
cator should be OFF. When pedal is
depressed, switch open, 0 V should be
at PA8, and indicator should be ON.
23
If there is no voltage at PA8, check
wire and connectors between VECU
and switch. If okay, check power sup-
ply to the switch. If okay, the fault is
most likely in the switch.
T2012911
Check that the indicator lamp in the
test lights up when the clutch pedal is
pressed down.
20
If the lamp does not light up when
the clutch pedal is depressed, the
cruise control function will not be
switched off while in cruise mode.
When the pedal is released (at rest),
the circuit to the control unit is closed.
Indicator lamp should be OFF.
Proceed with next step is not function-
ing properly.
NOTE: If the indicator lamp in the test
lights up continuously, the cruise
control function will not work.
Volvo Trucks North America, Inc. Date Group No. Page
Service Bulletin 11.2002 275 13 11(12)
Status pedal switch, brakes 26
Connect breakout harness 9990025
24 and breakout box 9998699 (use over-
lay 85104410; use 18pin scheme on
overlay) to LCM (Light Control Mod-
ule). Check resistance:
Measurement Expected value
point
LC1-12 (+) to open circuit
ground (pedal at rest;
switch closed)
< 10
(pedal
depressed;
switch open)
NOTE: Air system must be charged
with air before pressure switch will
function.
T2012912
Check that the indicator lamp in the
test lights up when the brake pedal is 27
pressed down. Connect breakout harness 9813194
and breakout box 9990014 (use over-
If the lamp does not light up or lay 85104407) to PA connector at
lights up continuously, carry out VECU. Connect breakout harness
checks in the same way as Status 9998533 and second breakout box
pedal switch, clutch page 10. 9990014 (use overlay 85104406) to
PB connector. Check voltage:
Measurement Expected value
point Measurement Expected value
point
PA5 (signal) - B+ V (pedal at
PA12 (ground) rest; switch PB27 (+) to open circuit
closed) PA12 (-) on (pedal at rest;
0 V (pedal de- VECU (A17) switch closed)
pressed; switch < 10
(pedal
open) depressed;
switch open)
Pressure switch, brake lamp NOTE: Air system must be charged
with air before pressure switch will
25 function.
Check that the indicator lamp lights up
when the brake pedal is depressed.
28
If the lamp does not light up, the brake If measurements are incorrect, check
test will not be approved. the connectors and wiring at pressure
Continue with next step; check ground switch, LCM, as well as at VECU.
signal to LCM. Check for loose connections and open
circuits. Refer to wiring diagram.
29
If the lamp does not light and the con-
nectors and electrical wiring and
pressure switch has correct ground,
the fault is most likely in the brake
pressure switch.
Page 12
Brake Test
30
For the cruise control to function, the
brake test must be approved (brakes
must be applied prior to cruise activa-
tion).
31
Check that the indicator lamp in the
test lights up after the pedal is de-
pressed. Lamp should remain lit after
pedal is depressed indicating that the
brake test has been approved.
Settings
Minimum speed, cruise control
1
Check that the value is within the per-
mitted range.
For information on parameter program-
ming, refer to the VCADS Pro User
manual.
Maximum speed, cruise control
2
Check that the value is within the per-
mitted range. The value must be below
the maximum value of the speed limits.
For information on parameter program-
ming, refer to the VCADS Pro User
manual.
Test Drive
1
Check that the set speed corresponds
to the actual speed when the cruise
control is active, i.e. when the vehicle
speed is checked by the cruise control
function.
2
Check that the indicator lamp in the
test lights up when the cruise control
is active, i.e. when the vehicle speed is
checked by the cruise control function.
