Operation CHARM: Car repair manuals for everyone.

Part 2






Reading off diagnostic trouble codes (DTCs), lock and alarm (VGLA), (Continued)

Checking power supply to Volvo Scan Tool (ST)








- Ignition on.
- Volvo Scan Tool (ST) wiring connected to the data link connector (DLC).
- Connect Volvo Scan Tool (ST) to the adapter box.
- Disconnect the 3-pin connector.
- Power switch on the adapter box ON.
Connect a voltmeter between 3-pin connector terminals:
- #1 (to data link connector (DLC)) and ground
- #3 (to data link connector (DLC)) and ground









The voltmeter should read 7-9 V between terminal 3 and ground, and battery voltage between terminal 1 and ground.

OK - Checking ground to Volvo Scan Tool (ST)

Not OK - Replacing component

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Replacing component
Try a new adapter box.

Continue - Verification

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Checking ground to Volvo Scan Tool (ST)








- Ignition off.
- Cabling to Volvo Scan Tool (ST) connected to the data link connector (DLC).
- 3-pin connector disconnected from Volvo Scan Tool (ST).
Connect an ohmmeter between the 3-pin connector terminal 2 (to the data link connector (DLC)) and ground.









The ohmmeter should read 0 ohms.

OK - Checking display activation

Not OK - Replacing component

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Checking display activation




- Ignition off.
- Connect Volvo Scan Tool (ST) to the adapter box and wiring.
- Connect Volvo Scan Tool (ST) to the data link connector (DLC).
- Ignition on.
Turn on power supply using the switch on the adapter box.
Check the Volvo Scan Tool (ST) display.

Does the display light?

Yes - Fault-tracing information

No - Replacing component

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Fault-tracing information
- The fault was probably caused by loose connections in connectors or wiring. Check the Volvo Scan Tool (ST), adapter box, wiring and data link connector (DLC) for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue - Verification

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Replacing component
Try a new Volvo Scan Tool (ST).

Continue - Verification

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Checking wiring








- Ignition off.
- Disconnect Volvo Scan Tool (ST).
- Disconnect wiring 1/6 meters.
Connect an ohmmeter between the 16-pin and 25-pin connectors according to the table below:














The ohmmeter should read 0 ohms in all readings.

OK - Checking for a short-circuit in the wiring

Not OK - Replacing component

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Checking for a short-circuit in the wiring








- Ignition off.
- Wiring 1/6 meters disconnected.
To find a short-circuit, all terminals/wires in the cable must be checked for a short-circuit to each other. Take readings in the 16-pin connector.
Connect an ohmmeter between the 16-pin connector terminal pins:
- #1 and the other terminals
- #2 and the other terminals
Take readings for the other terminals in the same way.









The ohmmeter should read infinite resistance for all readings.

OK - Checking communication with other diagnostic systems

Not OK - Replacing component

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Checking communication with other diagnostic systems








- Ignition off.
- Connect Volvo Scan Tool (ST) to the adapter box and wiring.
- Connect Volvo Scan Tool (ST) to the data link connector (DLC) and turn on the power supply using the switch on the adapter box.
- Ignition on.
Try to establish communication with the ABS control module by reading off diagnostic trouble codes (DTCs).





Has communication been established?

Yes - Fault-tracing information

No - Replacing component

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Replacing component
Try a new Volvo Scan Tool (ST) and adapter box.

Continue - Verification

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Checking for contact resistance and oxidation.




Check VGLA control module connector for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.




- Ignition on.
- Volvo Scan Tool (ST) connected.
Try to establish communication with the VGLA system by reading out the status for the driver's door door switch.

Has communication with the VGLA system been established?

Yes - Verification

No - Checking cables

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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 Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Check circuit before fuse 6 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check cable between fuse 6 and VGLA control module #B1 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check cable between VGLA control module #A1 and ground for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Other information:
- The voltage between VGLA control module #B1 and ground should be battery voltage.
Remedy as necessary.






Continue - Verification

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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.

Not OK - Checking for an open-circuit

OK - Checking the communication cable

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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 9-11V.

Low - Checking for a short-circuit

High - Checking for a short-circuit

OK - Checking communication with VGLA

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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 Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.





Continue - Verification

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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 Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.





Continue - Verification

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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 - Fault cause and checking for contact resistance and oxidation

No - Checking Volvo Scan Tool (ST)

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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 Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.





Continue - Verification

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Verification

Hint: After carrying out the repair, check that the fault has been remedied as follows.
that the fault is corrected 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 by reading out the status for the driver's door door switch.





Has communication with the VGLA system been established?

Yes - Fault has been remedied

No - Fault-tracing information

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Fault-tracing information




Information

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Do you want to exit fault-tracing?

Yes - Exit fault-tracing

No - Attempt New Test

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Fault-tracing information




Fault-tracing communication problems is now finished.

Do you want to try establishing communication again?

Yes - Repeat test

No - Exit fault-tracing

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