Toyota2008–2012

iQ 1.4 D-4D: Common faults & known problems

Common faults & known problems

7 known faults documented in workshop bulletins. Of these, three concern the engine and fuel system and one the brakes. Symptoms, causes, repair steps and part numbers are shown where supplied.

Engine & fuel system

3 documented faults — symptoms, causes and workshop fixes.

Poor cold starting

Overview

Affects
All models with 1ND-TV engine code, →12/09.
Remedy
Software update

Symptoms

Erratic idle when started from cold.

Cause

Faulty fuel injectors.

Engine control module (ECM) software fault.

Repair steps

  1. Carry out electrical, mechanical and component tests (as applicable) to eliminate any other possible cause(s).
  2. If no fault(s) found: Re-program ECM with upgraded software.
  3. Inspect part number on fuel injectors. If part number 23670-33050, replace fuel injectors.

Parts

Parts listed in the bulletin
PartPart numberQty
Fuel injector23670-330514

Data: Motorwise Workshop. Bulletin 1.

Fuel gauge fluctuates

Faulty fuel gauge tank sensor/ventilation assembly.

Overview

Affects
All models, →11/09.

Repair steps

  1. Remove fuel gauge tank sensor/ventilation assembly.
  2. Transfer fuel gauge tank sensor to new ventilation assembly.
  3. Fit fuel gauge tank sensor/ventilation assembly.

Data: Motorwise Workshop. Bulletin 2.

Engine oil leak from cylinder head area

Affects All models with 1.4 Diesel engine.Fit modified part

Cause

Cylinder head cover gasket damaged during assembly.

Repair

  1. Fit modified cylinder head cover gasket.
Parts1 part
Parts listed in the bulletin
PartPart numberQty
Cylinder head cover gasket11213-330311

Data: Motorwise Workshop. Bulletin 5.

Brakes

1 documented fault — symptoms, causes and workshop fixes.

Poor performance of parking brake

Affects All models with rear disc brakes, →03/12.Fit modified part

Cause

Unsatisfactory design of handbrake cables.

Repair

  1. Fit modified handbrake cables.
Parts2 parts
Parts listed in the bulletin
PartPart numberQty
Handbrake cable, left46430-740211
Handbrake cable, right46420-740211

Data: Motorwise Workshop. Bulletin 6.

Suspension & drivetrain

1 documented fault — symptoms, causes and workshop fixes.

Knocking noise from front suspension over uneven surfaces

Overview

Affects
All models.
Remedy
Fit modified part
Parts
1 part

Cause

Unsatisfactory design of front lower suspension arm front retaining bolt.

Repair

  1. Fit modified front lower suspension arm front retaining bolt.
  2. Tighten retaining bolts to the correct torque of 145±18 Nm.
Parts1 part
Parts listed in the bulletin
PartPart numberQty
Bolt90119-141502

Data: Motorwise Workshop. Bulletin 3.

Body & trim

1 documented fault — symptoms, causes and workshop fixes.

Door handles sticking in open position in very cold conditions

Affects All models, →03/09.Fit modified part

Cause

Door handle frozen due to poor water drainage.

Repair

  1. Fit modified door handles.

Data: Motorwise Workshop. Bulletin 7.

Other

1 documented fault — symptoms, causes and workshop fixes.

Poor performance or failure of AC system

Affects All models, →09/09.Fit modified part

Cause

AC compressor faulty.

Repair

  1. Fit modified AC compressor.

Data: Motorwise Workshop. Bulletin 4.

Glossary

Technical terms used in this guide.

ECM
Engine control module — the electronic unit that manages the engine
Nm
Newton-metres — the standard unit for how tightly a bolt is done up
AC
Air conditioning — the system that cools the cabin
Control Module
A control unit for one of the vehicle's systems (engine, gearbox, brakes, body, and so on)
Re-Program
Update the software on a control module using the manufacturer's diagnostic tool

Frequently asked questions

What are the common faults with the Toyota iQ 1.4 D-4D?

This guide contains seven workshop bulletins for the Toyota iQ 1.4 D-4D. Of these, three concern the engine and fuel system and one the brakes. Symptoms, causes, repair steps and part numbers are shown where supplied.

Does every Toyota iQ 1.4 D-4D 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 iQ 1.4 D-4D faults myself?

Many of them. The documented symptoms can be seen, heard or felt during a test drive.

Related guides

Glossary term

See in the glossary →