Fault Code | Possible cause | Action |
P0505 | ISC stepper motor I wiring fault | View & note diagnostic software 'freeze frame' data if available. View & note diagnostic software 'sensor' data. Ensure sensor connector is secure. Disconnect ECM and proceed to pinpoint test 1: |
Pinpoint Tests
Test | Result | Action |
1. Check cable and terminal integrity: ECM pin A20 ECM pin A21 ECM pin A22 ECM pin A23 | OK | Proceed to test 2 |
Faulty | Rectify fault, proceed to test 7 | |
2. Check resistance value: ECM pin A20 to ECM pin A21 ECM pin A22 to ECM pin A23 | 4 Ω to 12 Ω | Disconnect stepper motor and proceed to test 3 |
Open circuit | Disconnect stepper motor and proceed to test 4 | |
Short circuit | Disconnect stepper motor and proceed to test 5 | |
3. Check cable for short circuit: ECM pin A20 to earth ECM pin A21 to earth ECM pin A22 to earth ECM pin A23 to earth | OK | Proceed to test 7 |
Short circuit | Locate and rectify wiring fault, proceed to test 7 | |
4. Check cable continuity: ECM pin A22 to stepper motor pin A ECM pin A23 to stepper motor pin A 1 ECM pin A20 to stepper motor pin B ECM pin A21 to stepper motor pin B 1 | OK | Proceed to test 6 |
Open circuit | Locate and rectify wiring fault, proceed to test 7 | |
5. Check cable for short circuit: ECM pin A22 to ECM pin A23 ECM pin A20 to ECM pin A21 | OK | Proceed to test 6 |
Short circuit | Locate and rectify wiring fault, proceed to test 7 | |
6. Check stepper motor resistance: Motor pin A to motor pin A 1 Motor pin B to motor pin B 1 | 4 Ω to 12 Ω | Proceed to test 7 |
Faulty | Renew stepper motor, proceed to test 7 | |
7. Reconnect harness, clear fault code and run diagnostic software function test to visually verify operation of stepper motor | OK | Action complete - quit test |
Fault still present | Contact Triumph service |