Engine & fuel system
4 documented faults — symptoms, causes and workshop fixes.
Engine difficult to start
Spark plugs contaminated with carbon deposits.
Overview
- Affects
- All models with 1KR-FE engine code.
- Fault codes
P0420P0300P0303
Symptoms
Engine malfunction indicator lamp (MIL) illuminated. Engine misfire. Trouble codes stored: P0420, P0300, P0303.
Repair steps
- Replace spark plugs.
- Check operation and condition of catalytic converter. Replace if necessary.
- Check operation and condition of heated oxygen sensor (HO2S). Replace if necessary.
- Check for diagnostic trouble codes and delete as necessary.
Data: Motorwise Workshop. Bulletin 1.
Rattling noise from exhaust tail pipe when accelerating between 2500-3500rpm at normal operating temperature
Cause
Unsatisfactory design of front exhaust system causing rattling noise to be transmitted to exhaust tail pipe.
Repair
- Fit modified front exhaust system.
Parts3 parts
| Part | Part number | Qty |
|---|---|---|
| Front exhaust system | 17410-0Q022 | 1 |
| Exhaust sealing ring | 17451-40031 | 1 |
| Exhaust sealing ring | 17541-0Q010 | 1 |
Data: Motorwise Workshop. Bulletin 9.
Unable to remove in-tank fuel pump
Overview
- Affects
- All models with in-tank fuel pump assembly retaining ring.
- Remedy
- Fit new part
Cause
Retaining ring for fuel pump assembly seized to fuel tank.
Repair
- Cut through retaining ring to enable removal from fuel tank. Avoid damaging fuel tank threads.
- Inspect fuel tank threads for damage. If fuel tank threads damaged or new retaining ring will not tighten: Fit new fuel tank.
Data: Motorwise Workshop. Bulletin 14.
Engine malfunction indicator lamp (MIL) illuminated. Trouble code stored: P0420
Symptoms
Lack of power.
Cause
Catalytic converter breaks up internally and blocks exhaust system.
Repair
- Check operation and condition of catalytic converter. Replace if necessary.
Parts1 part
| Part | Part number | Qty |
|---|---|---|
| Catalytic converter | 17140-0Q020, or 17140-0Q010 | 1 |
Data: Motorwise Workshop. Bulletin 15.
Electrical & ignition
1 documented fault — symptoms, causes and workshop fixes.
No sound from speakers, even though audio unit switched on
Audio unit failure due to water ingress through roof aerial base.
Overview
- Affects
- All models.
Repair steps
- Check aerial lead for water ingress or corrosion. Replace as necessary.
- Remove roof aerial base.
- Apply sealant to roof aerial base and refit.
- Replace audio unit.
Data: Motorwise Workshop. Bulletin 10.
Brakes
6 documented faults — symptoms, causes and workshop fixes.
RH handbrake cable not secured correctly
Overview
- Affects
- All models built in France with rear disc brakes, →07/08.
- Remedy
- Fit modified part
- Parts
- 1 part
Cause
RH handbrake cable retaining clip faulty Fig.119609.1 .
Repair
- Fit modified RH handbrake cable.
- Replacement handbrake cable retaining clip not available separately.
Parts1 part
| Part | Part number | Qty |
|---|---|---|
| RH handbrake cable | 46420-0D060 | 1 |
Data: Motorwise Workshop. Bulletin 2.
ABS warning lamp illuminated
Symptoms
Possible trouble codes stored: C0210/33, C0215/34, C1332/37, C1333/38, C1241/41.
Cause
Water ingress into rear ABS wheel speed sensor(s) and wiring harness causing corrosion.
Repair
- Fit modified rear ABS wheel speed sensor and wiring harness.
Parts6 parts
| Part | Part number | Qty |
|---|---|---|
| Wiring harness, RH - except 1,8 | 89516-0D070 | 1 |
| Wiring harness, LH - except 1,8 | 89516-0D080 | 1 |
| Rear ABS wheel speed sensor - except 1,8 | 89544-0D030 | 2 |
| Wiring harness, RH - 1,8 | 89516-52090 | 1 |
| Wiring harness, LH - 1,8 | 89516-52100 | 1 |
| Rear ABS wheel speed sensor - 1,8 | 89544-52040 | 2 |
Data: Motorwise Workshop. Bulletin 4.
ABS warning lamp, brake system warning lamp and ESP warning lamp illuminated
Symptoms
Trouble code stored in ABS control module fault memory: C1246.
Cause
Internal failure of ABS hydraulic modulator due to corrosion.
Repair
- Fit new ABS hydraulic modulator.
Parts1 part
| Part | Part number | Qty |
|---|---|---|
| ABS hydraulic modulator | 44050-0D041 | 1 |
Data: Motorwise Workshop. Bulletin 7.
Squeal from rear brakes
Symptoms
Rear brake pads sticking.
Cause
Unsatisfactory design of rear brake pads.
Repair
- Fit modified rear brake pads.
Data: Motorwise Workshop. Bulletin 11.
Grinding noise from rear wheels
Overview
- Affects
- All models built in France with rear drum brakes, →04/11.
- Parts
- 3 parts
Cause
Insufficient clearance between rear brake drum and back plate.
Excessive play in rear wheel bearing.
Repair
- Check for excessive free play in rear wheel bearing. Replace component(s) as necessary.
- Check for adequate clearance between rear brake drum and back plate. Replace component(s) as necessary.
Parts3 parts
| Part | Part number | Qty |
|---|---|---|
| RH rear brake drum back plate | 47043-0950 | 1 |
| LH rear brake drum back plate | 47044-0950 | 1 |
| Rear wheel bearing kit | 42450-0D05G | 1 |
Data: Motorwise Workshop. Bulletin 12.
Engine malfunction indicator lamp (MIL) illuminated. Possible trouble codes stored: C1249, P0571
Overview
- Affects
- All models built in France, →12/09.
- Fault codes
C1249P0571
Cause
Brake pedal position (BPP) switch incorrectly fitted.
Repair
- Check operation of BPP switch, replace if necessary.
- Ensure BPP switch fitted correctly.
Data: Motorwise Workshop. Bulletin 13.
Steering
1 documented fault — symptoms, causes and workshop fixes.
Abnormal noise from steering when steering wheel turned
Cause
Unsatisfactory design of steering column.
Repair
- Fit modified steering column.
Data: Motorwise Workshop. Bulletin 8.
Body & trim
3 documented faults — symptoms, causes and workshop fixes.
Difficult to unlock front doors using key
Symptoms
Key remote control has to be pressed several times to unlock doors.
Cause
Unsatisfactory design of front door lock mechanism.
Repair
- Fit modified door lock mechanisms.
Data: Motorwise Workshop. Bulletin 3.
Wind noise from door mirror when driving at approximately 60mph (100kph)
Cause
Door mirror mounting trim cover not fitted correctly.
Repair
- Ensure door mirror mounting trim cover fitted correctly.
Data: Motorwise Workshop. Bulletin 5.
Tailgate fails to fully open
Cause
Tailgate gas struts faulty.
Repair
- Renew tailgate gas struts.
Parts2 parts
| Part | Part number | Qty |
|---|---|---|
| Gas strut - RH | 68950-0D022 | 1 |
| Gas strut - LH | 68960-0D012 | 1 |
Data: Motorwise Workshop. Bulletin 6.
Glossary
Technical terms used in this guide.
- MIL
- Malfunction indicator lamp — the engine warning light on the dashboard
- ABS
- Anti-lock braking system — stops the wheels locking under hard braking
- BPP Switch
- Brake pedal position switch — behind the pedal, it triggers the brake lights
- Trouble Codes
- Standardised fault codes stored by the engine control module, read with a diagnostic tool
- BPP
- Brake pedal position — the switch behind the pedal that triggers the brake lights
- RH
- Right-hand — the right side of the vehicle as you sit in it
- RHD
- Right-hand drive — steering wheel on the right
- Control Module
- A control unit for one of the vehicle's systems (engine, gearbox, brakes, body, and so on)
- Fault Memory
- The list of stored trouble codes in a control module
- In-Tank Fuel Pump
- The fuel pump mounted inside the fuel tank
- Trouble Code
- A standardised fault code stored by a control module, read with a diagnostic tool
- Wheel Speed Sensor
- A sensor at each wheel used by ABS and stability control
- Wiring Harness
- The bundled cables that carry power and signals around the vehicle
- Misfire
- One or more cylinders not firing correctly — the engine runs roughly or loses power
Frequently asked questions
What are the common faults with the Toyota Yaris 1.0 VVT-i?
This guide contains 15 workshop bulletins for the Toyota Yaris 1.0 VVT-i. Of these, six concern the brakes and four the engine and fuel system. Symptoms, causes, repair steps and part numbers are shown where supplied.
Does every Toyota Yaris 1.0 VVT-i have these faults?
No. These are patterns documented across the model by workshops, not predictions for an individual vehicle. Where a fault applies only to certain vehicles or VIN ranges, that is listed with the fault.
Can I check for Toyota Yaris 1.0 VVT-i faults myself?
Many of them. The documented symptoms can be seen, heard or felt during a test drive.