ABS-322
L. ABS-321, ABS-322 Wheel sensor signalABS-321 Wheel sensor signal LH front wheel, extrapolation counter
ABS-322 Wheel sensor signal RH front wheel, extrapolation counter
LA. 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 fault code ABS-321 or ABS-322, depending on the wheel sensor involved.
Substitute value
- ABS/TRACS cuts out
- EBD system is available.
Possible source
- Loose contact in the cabling or shoes.
- Damaged insulation on leads.
- The earth and signal cables 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 the connections
Fault symptom(s)
- If the ABS function cuts out, there is a risk of the wheels locking when braking.
- In cars with TRACS, the anti-wheelslip system cuts out.
Caution! If the fault becomes intermittent, the ABS warning light will go out once the speed exceeds 20 km/h (12 mph) in the next driving cycle.
Fault-tracing begins with LB. Other DTCs, status notifications and status checks.
LB. Other DTCs, status notifications and status checks
[LB1]
Status notification
Is a permanent fault posted?
Yes: LB2
No: Fault-trace as per LD. Extrapolation counter. Intermittent fault.
[LB2]
Other DTCs
- Note other DTCs
Select one of the following alternatives to continue
Alternative 1: Fault-trace as per LC. Extrapolation counter. Permanent fault.
Alternative 2: LB3
[LB3]
ABS-321 or ABS-322, and ABS-311 or ABS-312 (for the same wheel)
Fault-trace as per JC. Circuit fault. Permanent fault ABS-311
Then continue with: Fault-trace as per LC. Extrapolation counter. Permanent fault..
LC. Extrapolation counter. Permanent fault.
[LC1]
Connect the test box and check the control points
Connect test box as per [JJJA]. Connect the test box Pinout Values and Diagnostic Parameters
Then proceed to: LC2
[LC2]
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: LC6
If reading is incorrect: LC3
[LC3]
Check the resistance in the wheel sensor
- Ignition off
- Remove the wheel for better access
- Clean carefully around the wheel sensor connector. Brush and blow clean
- Disconnect the wheel sensor
Connect an ohmmeter between wheel sensor connector connection 1 and 2.
The ohmmeter should indicate approx. 1040-1160 ohms.
If reading is OK: LC4
If reading is incorrect: LC5
[LC4]
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 the wheel sensor connector [IIIB5]. Check Communication to Control Module [III]
Then continue with: LC17
[LC5]
Replace the component
Test with a new wheel sensor as per KKKKA. Front wheel sensor, replacement
Sensors and Switches - Brakes and Traction Control - Wheel Speed Sensor - Service and Repair - Procedures Service and Repair
Then continue with: LC17
[LC6]
Check the signal leads
- Ignition off
- Connect the control module.
- Ignition on
Connect a voltmeter between the 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: LC9
If value is higher: LC8
If value is lower: LC7
[LC7]
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 wheel sensor connector connection:
1 and control module #11 (DTC ABS- 321)
2 and control module #4 (DTC ABS-321)
1 and control module #18 (DTC ABS-322)
2 and control module #3 (DTC ABS-322)
for short-circuiting to ground as per [IIIB3]. Check Communication to Control Module [III]
Then continue with: LC17
[LC8]
Check for short circuiting
Check the cable between wheel sensor connector connection:
1 and control module #11 (DTC ABS-321)
2 and control module #4 (DTC ABS-321)
1 and control module #18 (DTC ABS-322)
2 and control module #3 (DTC ABS-322)
for short circuiting to power as per [IIIB4]. Check Communication to Control Module [III]
Then continue with: LC17
[LC9]
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: LC11
If reading is incorrect: LC10
[LC10]
Action
Take appropriate action as needed. The front wheel bearings are not adjustable.
Then continue with: LC17
[LC11]
Check the wheel sensor
- Ignition off
Note! Do not disconnect the wheel sensor.
- Remove the wheel for better access.
Check that the wheel sensor is fitted against the spindle/hub. There should be no dirt between the sensor and the contact surfaces.
- Remove the wheel sensor as per KKKKA. Front wheel sensor, replacement.
Sensors and Switches - Brakes and Traction Control - Wheel Speed Sensor - Service and Repair - Procedures Service and Repair
Check that the wheel sensor point is undamaged
Is the wheel sensor OK ?
If reading is OK: LC13
If reading is incorrect: LC12
[LC12]
Take appropriate action or replace the component.
Replace a damaged wheel sensor as per KKKKA. Front wheel sensor, replacement.
Refit a loose sensor as per [KKKKA]. Front wheel sensor, replacement.
Sensors and Switches - Brakes and Traction Control - Wheel Speed Sensor - Service and Repair - Procedures Service and Repair
Then continue with: LC17
[LC13]
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: LC15
If reading is incorrect: LC14
[LC14]
Action
Take appropriate action as needed.
Then continue with: LC17
[LC15]
Check the leads and connections
Check the wheel sensor and control module connectors for contact resistance and oxidation [IIIB5]. Check Communication to Control Module [III]
Check the cable between wheel sensor connector connection:
1 and #11 (DTC ABS-321)
2 and #4 (DTC ABS-321)
1 and #18 (DTC ABS-322)
2 and #3 (DTC ABS-322)
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: LC16
[LC16]
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 telephone leads etc.
Then continue with: LC17
[LC17]
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: LC18
[LC18]
Fault-tracing information
The verification result shows that the fault persists.
Do you want to exit fault-tracing?
Yes: Fault not corrected
No: LC1
LD. Extrapolation counter. Intermittent fault.
[LD1]
Check the wheel sensor and pulse wheel
Check that the wheel sensor is fitted securely to the spindle/hub
Then continue with: LD2
[LD2]
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: LD3
[LD3]
Check the leads and connections
Check the wheel sensor and control module connectors for contact resistance and oxidation as per [IIIB6]. Check Communication to Control Module [III]
Check the cable between wheel sensor connector connection:
1 and #11 (DTC ABS-321)
2 and #4 (DTC ABS-321)
1 and #18 (DTC ABS-322)
2 and #3 (DTC ABS-322)
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: LD4
[LD4]
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: LD1
No: Operation done