F21 ABS not working: wheel locked
- Make
- Fiat
- Model
- Seicento Factory Service Manual
- Year
- 1998–2010
- Section
- Brakes › F21 ABS not working: wheel locked
DiagnosisF21 ABS not working: wheel locked
F21 ABS not working: wheel locked
Operating the brakes suddenly and forcefully (“panic” braking), the ABS does not work correctly. Consequently, a wheel is locked
| Step | Validity | Operation to be performed | Test results | ||
|---|---|---|---|---|---|
| OK | ⚠ | 🔧 | |||
| 1 | CHECK “ABS FAULT” WARNING LIGHT | Turn the key to MAR and check whether the “ABS fault” warning light comes on for 4 seconds and then comes off | All OK Go to Step 2 |
Problems found The “ABS fault” warning light comes on and stays on |
Intervention See table K60 |
| 2 | CHECK WITH DIAGNOSTIC TOOL | Connect diagnostic tool (Examiner or other tool) to the diagnostic socket. Check in sequence: – no faults in ABS ECU – plausibility of all parameters |
All OK Go to Step 3 |
Problems found Failed dialogue with ECU |
Intervention Restore connection between ABS ECU and diagnostic socket (Wiring diagram: E7020 “ABS”) |
| Error detected in ECU | Intervention Continue as shown by the diagnostic tool |
||||
| 3 | Perform active test with diagnostic tool With the diagnostic tool (Examiner or other tool) perform the following active tests: – pump motor; – solenoid valves; – speed sensors |
All OK Go to Step 4 |
Problems found Detected fault in solenoid valve |
Intervention Replace electric hydraulic unit - ECU PROCEDURE OP. 334CA10 |
|
| Detected fault in sensor | Intervention Replace sensor PROCEDURE OP. 3340A30 (front) o 3340A34 (rear). If the fault persists, check intactness and cleanliness of wheel hub |
||||
| 4 | CHECK PRESENCE OF AIR | Check for air in the system | All OK Go to Step 5 |
Problems found Air in the system |
Intervention Bleed the system PROCEDURE OP. 3330A14 |
| 5 | CHECK CORRECT OPERATION | Check the fault is no longer present | All OK End of test |
Problems found -- |
Intervention -- |
Parts & tools for this job For 1998 Fiat Seicento
- TOOLOBD2 scanner with ABSSearch: OBD2 scanner ABS SRS
- TOOLDigital multimeterSearch: automotive digital multimeter
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