IMPACT 4.07.
140 25/06/2022
Chassis ID Path
A 712695 3649/Diagnostics//MID 144 PID 84 Vehicle speed, check
Model Identity
FM 150339761
Publish date ID/Operation
21/01/2020 36463-3
36463-3 MID 144 PID 84 Vehicle speed, check
Special tools: 9990008, 9998534
Other special equipment: 9812519
NOTE!
Read off the other fault codes for the vehicle control unit, tachograph and brakes control unit.
Switch off the power in the vehicle before the connectors are disconnected.
Check the relevant connectors, while fault tracing, with regard to loose connections, resistance and oxidation. For
further descriptions of fault tracing in wiring and connectors, see separate service information under group 371.
Tests that can be carried out in the PC tool
The following tests can be used to examine component function in more detail:
Cruise control, switch, test.
The test makes it possible to read speed signals from the vehicle control unit.
Measurement at the component connector, towards the control unit
Note: Faults in the cable harness to the control unit can damage the component. So if a reading is outside its
permitted range check the component as well.
Tachograph
1
Conditions:
Connectors marked B on the back of the tachograph disconnected.
Measurement with test pins connected to the cable harness at connectors A and B for the tachograph.
Voltage measurement using a multimeter.
Control unit connected.
Starter switch in ON position:
Measurement points Expected value
A4 - ground U ≈ 3.4 V
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
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IMPACT 4.07.140 25/06/2022
A8 - ground U ≈ 1.75 V
Conditions:
Resistance measurement using a multimeter.
Control unit connected.
Starter key in stop position.
Measurement points Expected value
B7 - ground R ≈ 7 k–8 k Ω
Special tools: 9990008
Other special equipment: 9812519
Speedometer
2
Note: The check below only applies to vehicles equipped with a speedometer.
Conditions:
The connector to the speed sensor disconnected.
Adapter connected to cable harness.
Resistance measurement using a multimeter.
Control unit connected.
Starter key in stop position.
Measurement at the control unit.
Measurement points Expected value
3-2 R ≈ 90 - 130 k Ω
Special tools: 9998534
Other special equipment: 9812519
Conditions:
The connector to the speed sensor disconnected.
Adapter connected to cable harness.
Voltage measurement using a multimeter.
Control unit connected.
Ignition key in the drive position.
Measurement at the control unit.
Measurement points Expected value
1-2 U ≈ 20 V - Ubat
Special tools: 9998534
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
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IMPACT 4.07.140 25/06/2022
Other special equipment: 9812519
Cable harness
4
For checking the cable harness, see service information under group 371.
Component check
Note: A fault in the component may have been caused by a fault in the control unit cable harness. Check the cable
harness before connecting a new component.
Tachograph
Note: Read off and rectify the fault codes for the tachograph.
Speedometer
Note: No relevant measurement.
Check sub-systems
Tachograph
1
Conditions:
Measurement between tachograph and cable harness.
Voltage measurement using a multimeter.
Ignition key in the drive position.
Measurement points Expected value
A4 - ground U ≈ 2.5 V
A8 - ground U ≈ 2.5 V
B7 - ground U ≈ 2.3 V
Special tools: 9990008
Other special equipment: 9812519
Speedometer
2
Conditions:
Measurement box with adapter connected between the speed sensor and the cable harness.
Resistance measurement using a multimeter.
Control unit connected.
Starter key in stop position.
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
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IMPACT 4.07.140 25/06/2022
Measurement points Expected value
2 - ground R≈0Ω
Special tools: 9998534
Other special equipment: 9812519
Supply cable
3
Conditions:
Measurement box with adapter connected between the speed sensor and the cable harness.
Voltage measurement using a multimeter.
Control unit connected.
Ignition key in the drive position.
Measurement points Expected value
1-2 U ≈ 6.5-9 V
Special tools: 9998534
Other special equipment: 9812519
Signal cable
4
Conditions:
Measurement box with adapter connected between the speed sensor and the cable harness.
Voltage measurement using a multimeter.
Ignition key in the drive position.
Measurement points Expected value
2-3 U ≈ 0.3-9.5 V
Special tools: 9998534
Other special equipment: 9812519
Verification
To check that the fault is rectified, use tests in the PC tool (seeTests that can be carried out in the PC tool).
Copyright to this documentation belongs to the Volvo Group. No reproduction, copying, change, amendment or other similar disposal is entitled without prior written consent by
the Volvo Group
The information contained herein is current at the time of its original distribution, but is subject to change. The reader is advised that printed copies are uncontrolled.
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