ABS-441

Q. ABS-441 Main control module relay

QA. DTC information

Condition

If the control module registers that there is no 30-supply from the control module main relay to the valves, DTC ABS-441 is posted.

Substitute value

- ABS/TRACS is disabled.
- EBD is disabled.

Possible source

- Defective control module

Note! For some control modules the diagnostic trouble codes (DTCs) can be posted for the following faults.

- Fuse 14 defective (for 850 diesel, fuse 11A/4).
- Break in voltage supply (30-supply) to control module #9
- Contact resistance in the connections.
These control modules can be identified by the identification code in the lower left corner of the control module product plate beginning with "S1...."

Fault symptom(s)

- If the ABS/EBD systems are disabled, there is a risk of the wheels (especially the rear wheels) locking when braking.
- In cars with TRACS, the anti-wheelslip system cuts out.

Fault-tracing begins with QB. Status notification.

QB. Status notification

[QB1]

Status notification

Select one of the following alternatives to continue.

Alternative 1: Fault-trace as per QC. Permanent fault
Alternative 2: Fault-trace as per QD. Intermittent fault

QC. Permanent fault

[QC1]

Identification of control module version

Different fault-tracing should be carried out depending on the control module version. Note the identification code in the lower left corner of the control module product plate.
Does the identification code begin with "S1...."?

Yes: QC2
No: QC11

[QC2]

Connection of test box and check of control points

Connect test box as per JJJA. Connect the test box Connect the Test Box [JJJ]

Then proceed to: QC3

[QC3]

Check the 30v supply to the control module

- Ignition off.
- Control module disconnected.

Connect a voltmeter between #8 and #9 on the test box.
The voltmeter should indicate the battery voltage.

If reading is OK: QC9
If reading is incorrect: QC4

[QC4]

Checking fuse

Checking that fuse 11/14 is intact (fuse 11A/4 for the 850 diesel)
Is the fuse intact?

Yes: QC6
No: QC5

[QC5]

Checking for short-circuit and replacing component

Check wire between fuse 11/14 and control module #9 for short-circuit to ground according to [IIIB3]. (For 850 diesel, check the wire between fuse 11A/4 and control module #9, and fuse 11A/4 and #25 for short-circuit to ground according to [IIIB3].) Check Communication to Control Module [III]
Then replace the fuse

Then continue with: QC12

[QC6]

Checking voltage before the fuse

Connect a voltmeter between the rear fuse holder socket for fuse 11/14 and ground (For 850 diesel pin in fuse 11A/4 applies.)
The voltmeter should read battery voltage.

If reading is OK: QC7
If reading is incorrect: QC8

[QC7]

Checking for an open-circuit in the wire

Check wire between fuse 11/14 and the control module #9 for for open circuit according to [IIIB2] (For 850 diesel fuse 11A/4 applies) Check Communication to Control Module [III]

Then continue with: QC12

[QC8]

Checking tor an open-circuit in the wire

Check wire between fuse 11/14 and the battery for open circuit according to [IIIB2]. (For 850 diesel fuse 11A/4 applies) Check Communication to Control Module [III]

Then continue with: QC12

[QC9]

Check the control module

- Ignition off.
- Disconnect the test box.
- Connect the control module.
- Disconnect the Volvo System Tester to abort the diagnosis.

Warning! The ABS and EBD systems are not available while Volvo Diagnostics is activated. Take great care when test driving as there is a serious risk of the wheels locking when braking.

Test drive the vehicle.
Note the DTC status. Is the status intermittent?

Yes: QC10
No: QC11

[QC10]

Check for contact resistance and oxidation

The cause of the fault has been poor contact in the control module contact
Check the control module manual contact for contact resistance and oxidation and take appropriate action [IIIB5]. Check Communication to Control Module [III]

Then continue with: Fault corrected

[QC11]

Replacing a component

Test with a new control module MMMM. Control module, replacement.
Relays and Modules - Brakes and Traction Control - Electronic Brake Control Module - Service and Repair - Procedures Service and Repair

Then continue with: QC12

[QC12]

Verification

Hint: After repair it is necessary to check that the fault has been rectified

- Ignition off
- 11 contacts, components etc. remain

Disconnect the Volvo System Tester to abort the diagnosis

Warning! The ABS and EBD systems are not available while Volvo Diagnostics is activated. Take great care when test driving as there is a serious risk of the wheels locking when braking

Test drive the vehicle as per [SA]. Test driving. Test Driving [SA]
Note the DTC status. Is the status intermittent ?

Yes: Fault corrected
No: QC13

[QC13]

Fault-tracing information

The verification result shows that the fault persists.
Do you want to exit fault tracing?

Yes: Fault not corrected
No: QC2

QD. Intermittent fault

[QD1]

Identification of control module version

Check the cable between the battery plus terminal and control unit #9 for intermittent breaks [IIIB2]. Check Communication to Control Module [III]

Then continue with: QD3

[QD3]

Erasing DTCs

- Ignition on
- Erase the DTC

Then continue with: QD4

[QD4]

Fault-tracing information

For intermittent faults fault-tracing is not followed by a verification because the fault is not present at this moment.
Do you want to repeat fault-tracing?

Yes: QD2
No: Operation done