VV. Checking Control Module Communication

VVA. Fault Tracing

Condition





The fault is permanent.
Correct memory cassette being used.
Alarm disarmed

Possible Source
Poor battery voltage.
Open-circuit, short-circuit to ground or short-circuit to supply voltage in cable to data link connector (DLC).
Open-circuit in data link connector (DLC) supply voltage or ground.
Defective Volvo Scan Tool (ST), adapter or wiring.

Start fault-tracing with VVB.


VVB1. Checking Power Supply





Ignition on.
Volvo Scan Tool (ST) connected to data link connector (DLC).
Power up the Volvo Scan Tool (ST) and check that the display lights.
Does the display light?
Yes: Go to VVB2.
No: Go to VVB5.


VVB2. Checking Communication With The ABS System

Ignition on.
Volvo Scan Tool (ST) connected to data link connector (DLC).
Try to establish communication with the ABS system.
Has communication with the ABS system been established?
Yes: Go to VVB3.
No: Go to VVB8.


VVB3. Check Function

Remove key from ignition switch.
Try to lock and unlock the car with the key.
Can the car be locked and unlocked?
Yes: Go to VVB4.
No: Go to VVB6.


VVB4. Checking For An Open-Circuit





Check cable between data link connector (DLC) terminal 7 and VGLA control module #B19 for an open-circuit according to WWA2 WW. Checking Wiring and Connections Then continue with VVB14.


VVB5. Checking Volvo Scan Tool (ST)

Check the Volvo Scan Tool (ST), power supply and data link connector (DLC) ground. Then continue with VVB14.


VVB6. Checking For Contact Resistance and Oxidation





Check VGLA control module connector for contact resistance and oxidation according to WWA5 WW. Checking Wiring and Connections
Ignition on.
Volvo Scan Tool (ST) connected.
Try to establish communication with the VGLA system.
Has communication with the VGLA system been established?
No: Go to VVB7.
Yes: Fault corrected


VVB7. Checking Cables





Ignition off.
Disconnect VGLA control module.
Check fuse 6.

Hint: If fuse 6 has blown, fault-trace the circuit after fuse 6 for a short-circuit to ground according to WWA3, for further information about the circuit after the fuse WW. Checking Wiring and Connections

Check circuit before fuse 6 for an open-circuit according to WWA2. Check cable between fuse 6 and VGLA control module #B1 for an open-circuit according to WWA2. Check cable between VGLA control module #A1 and ground for an open-circuit according to mWWA2 WW. Checking Wiring and Connections


Other Information:
The voltage between VGLA control module #B1 and ground should be battery voltage. Remedy as necessary. Then continue with VVB14.


VVB8. Checking Communication Cable To Data Link Connector (DLC)





Ignition off.
VGLA control module disconnected.
Disconnect Volvo Scan Tool (ST) from data link connector (DLC).
Connect an ohmmeter between data link connector (DLC) terminal 7 and VGLA control module connector #B19.
The ohmmeter should read approximately 0 Ohms.

If reading is incorrect: Go to VVB4.
If reading is OK: Go to VVB9.


VVB9. Checking The Communication Cable





Ignition off.
Connect control module.
Ignition on.
Connect a voltmeter between data link connector (DLC) terminal 7 and ground. The voltmeter should read approximately 9-11 V.

If value is lower: Go to VVB10.
If value is higher: Go to VVB11.
If reading is OK: Go to VVB12.


VVB10. Checking For A Short-Circuit





Check cables between data link connector (DLC) terminal 7 and control modules connected to this cable for a short-circuit to ground according to WWA3 WW. Checking Wiring and Connections Then continue with VVB14.


VVB11. Checking For A Short-Circuit






Check cables between data link connector (DLC) terminal 7 and control modules connected to this cable for a short-circuit to supply voltage according to WWA4 WW. Checking Wiring and Connections Then continue with VVB14.


VVB12. Checking Communication With VGLA:





Ignition on.
Volvo Scan Tool (ST) connected to data link connector (DLC).
Try to establish communication with the VGLA system. Has communication with the VGLA system been established?
Yes: Go to VVB13.
No: Go to VVB5.


VVB13. Fault Cause and Checking For Contact Resistance and Oxidation


The cause of the fault has been loose connections in the data link connector (DLC) and/or VGLA control module connectors. Check data link connector (DLC) and VGLA control module connectors for contact resistance and oxidation and remedy according to WWA5 WW. Checking Wiring and Connections Then continue with VVB14.


VVB14. Verification





Hint: After carrying out the repair, check that the fault has been remedied as follows:

Ignition off.
Reconnect connectors, reinstall components.
VGLA control module connected.
Ignition on.
Volvo Scan Tool (ST) connected to data link connector (DLC).
Try to establish communication with the VGLA system.
Has communication with the VGLA system been established?
Yes: Fault corrected
No: Fault not found