ABS-324
M. ABS-323, ABS-324 Wheel sensor signalABS-323 Wheel sensor signal LH rear wheel, extrapolation counter
ABS-324 Wheel sensor signal RH rear wheel, extrapolation counter
MA. DTC information
Substitute value
The control module has a counter, the extrapolation counter which counts the number of times the change in the speed of the wheel is too great compared to the expected figure (estimated). If the signal from the wheel sensor is affected by electromagnetic interference, varies too much, or is subject to short intermittent open- circuit/short-circuits, the control module interprets this to mean that the change in road speed is too large and updates the counter. Once the counter value exceeds 22, it sets DTC ABS-323 or ABS-324 depending on the wheel sensor involved.
Substitute value
- ABS/TRACS-system cuts out.
- EBD-system is available.
Possible source
- Loose contact in the cabling or shoes.
- Damaged insulation on leads.
- The ground and signal leads are too close to a source of interference.
- Loose wheel sensor
- Defective wheel sensor
- Defective pulse wheel
- Play in wheel bearing or axle vibration
- Contact resistance in connections
Fault symptom(s)
- If the ABS system cuts out, there is a risk of the wheels locking when braking.
- In vehicles with TRACS, the anti-wheel spin system cuts out.
Caution! If the fault becomes intermittent, the ABS warning light will only go out once the speed exceeds 20 km/h (12.5 mph) in the next driving cycle.
Fault-tracing begins with MB. Other DTCs, status notifications and status checks.
MB. Other DTCs, status notifications and status checks
[MB1]
Status notification
Is a permanent fault posted?
Yes: MB2
No: Fault trace as per MD. Extrapolation counter. Intermittent fault..
[MB2]
Other DTCs
Select one of the following alternatives to continue
Alternative 1: Fault-trace as per MC. Extrapolation counter. Permanent fault.
Alternative 2: MB3
[MB3]
ABS-323 or ABS-324, and ABS-313 or ABS-314 (for the same wheel)
Fault-trace as per KC. Circuit fault. Permanent fault. ABS-313
Then continue with: Fault-trace as per MC. Extrapolation counter. Permanent fault.
MC. Extrapolation counter. Permanent fault
[MC1]
Connect the test box and check the control points
Connect test box as per. JJJA. Connect the test box Connect the Test Box [JJJ]
Then proceed to: MC2
[MC2]
Check the resistance In the wheel sensor circuit
- Ignition off
- Control module disconnected
Connect an ohmmeter between test box:
#2 and #10 (DTC ABS-323).
#1 and #17 (DTC ABS-324).
The ohmmeter should indicate 1040-1160 ohms.
If reading is OK: MC6
If reading is incorrect: MC3
[MC3]
Check the resistance in the wheel sensor
- Ignition off
- Disconnect the wheel sensor
Connect an ohmmeter between wheel sensor connector 24/19 connection
1 and 3 (DTC ABS-323).
2 and 4 (DTC ABS-324).
The ohmmeter should indicate 1040-1160 ohms.
If reading is OK: MC4
If reading is incorrect: MC5
[MC4]
Check for contact resistance and oxidation
- The fault has been caused by poor contact in the wheel sensor connector.
Take appropriate action for contact resistance and oxidation in wheel sensor connector 24/19, 24/4B and 24/2B as per [IIIB5]. Check Communication to Control Module [III]
Then continue with: MC17
[MC5]
Check for cable breaks, short circuiting and replace the component
Check the leads between the wheel sensor and connector 24/19 for breaks as per [IIIB2] and short circuiting to each other as per xx. Check Communication to Control Module [III]
If the leads are OK. Test with a new wheel sensor as per LLLLA. Rear wheel sensor, with integrated cabling, replacement.
Sensors and Switches - Brakes and Traction Control - Wheel Speed Sensor - Service and Repair - Procedures Service and Repair
Then continue with: MC17
[MC6]
Check the signal leads
- Ignition off
- Connect the control unit
- Ignition on
Connect a voltmeter between test box:
#8 and #10 (DTC ABS-323).
#8 and #17 (DTC ABS-324).
The voltmeter should indicate approx. 2.3 V.
If reading is OK: MC9
If value is higher: MC8
If value is lower: MC7
[MC7]
Check for short circuiting
Check the wheel sensor for short circuiting to ground as per [IIIB3]. Check Communication to Control Module [III]
Check the cable between connector 24/19 connection:
1 and control module #2 (DTC ABS- 323)
3 and control module #10 (DTC ABS-323)
2 and control module #1 (DTC ABS-324)
4 and control module #17 (DTC ABS-324)
for short-circuiting to ground as per [IIIB3]. Check Communication to Control Module [III]
Then continue with: MC17
[MC8]
Check for short circuiting
Check the cable between connector 24/19 connection:
1 and control module #2 (DTC ABS-323)
3 and control module #10 (DTC ABS-323)
2 and control module #1 (DTC ABS-324)
4 and control module #17 (DTC ABS-324)
for short-circuiting to power as per [IIIB4]. Check Communication to Control Module [III]
Then continue with: MC17
[MC9]
Check the wheel bearing
Check that there is no play in the wheel bearing of the wheel in question and that it does not jam.
Is the wheel bearing OK?
If reading is OK: MC11
If reading is incorrect: MC10
[MC10]
Action
Take appropriate action as needed. The rear wheel bearings are adjusted.
Then continue with: MC17
[MC11]
Check the wheel sensor
- Ignition off
Note! Do not disconnect the wheel sensor
Check that the wheel sensor is fitted against the spindle/hub. There should be no dirt between the wheel sensor and the contact surfaces.
- Remove the wheel sensor as per LLLLA. Rear wheel sensor, with integrated cabling, replacement. Check that the wheel sensor point is undamaged.
- Sensors and Switches - Brakes and Traction Control - Wheel Speed Sensor - Service and Repair - Procedures Service and Repair
Is the wheel sensor OK ?
If reading is OK: MC13
If reading is incorrect: MC12
[MC12]
Take appropriate action or replace the component
Refit a loose wheel sensor as per LLLLA. Rear wheel sensor, with integrated cabling, replacement.
Replace a damaged wheel sensor as per LLLLA. Rear wheel sensor, with integrated cabling, replacement.
Sensors and Switches - Brakes and Traction Control - Wheel Speed Sensor - Service and Repair - Procedures Service and Repair
Then continue with: MC17
[MC13]
Check the pulse wheel
- Remove the wheel of the pulse wheel in question. Check that the pulse wheel is fitted securely, is undamaged (all teeth in place), free from scratches etc.
Is the pulse wheel OK ?
If reading Is OK: MC15
If reading is Incorrect: MC14
[MC14]
Action
Take appropriate action as needed
Then continue with: MC17
[MC15]
Check the leads and connections
Check the control module connectors 24/19, 24/4B and 24/2B and the wheel sensor connector for contact resistance and oxidation as per [IIIB5] Check Communication to Control Module [III]
.
Check the leads between the wheel sensor and control module:
#2 and #10 (DTC ABS-323)
#1 and #17 (DTC ABS-324)
for intermittent short circuiting to ground as per [IIIB3], intermittent short circuiting to power as per [IIIB4] and intermittent breaks as per [IIIB2]. Check Communication to Control Module [III]
Then continue with: MC16
[MC16]
Check for interference
Check that the wheel sensor cable is not too close to a source of interference e.g. electric motor, ignition leads, mobile phone cable etc.
Then continue with: MC17
[MC17]
Verification
Hint: After repair it is necessary to check that the fault has been rectified
- Ignition off
- Reconnect the connections, components etc.
- Disconnect Volvo System Tester so that the diagnosis is aborted.
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]
- Stop the vehicle.
Note the DTC status.
Is the fault intermittent ?
Yes: Fault corrected
No: MC18
[MC18]
Fault-tracing information
The verification result shows that the fault persists.
Do you want to exit fault-tracing?
Yes: Fault not corrected
No: MC1
MD. Extrapolation counter.. Intermittent fault.
[MD1]
Check the wheel sensor and pulse wheel
Check that the wheel sensor is fitted securely against the spindle/hub.
Check that the pulse wheel is fitted securely to the hub (DTC ABS-323, ABS-324).
Then continue with: MD2
[MD2]
Check the wheel bearing
Check that there is no play in the wheel bearing of the wheel in question and that it does not jam.
Then continue with: MD3
[MD3]
Check the leads and connections
Check wheel sensor connectors 24/19, 24/4B and 24/2B for contact resistance and oxidation [IIIB6]. Check Communication to Control Module [III]
Check the leads between the wheel sensor and control module:
#2 and #10 (DTC ABS-323)
#1 and #17 (DTC ABS-324)
for intermittent breaks as per [IIIB2], intermittent short circuiting to ground as per [IIIB3] and intermittent short circuiting to power as per [IIIB4] Check Communication to Control Module [III]
Then continue with: MD4
[MD4]
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: MD1
No: Operation done