Toyota2002–2006

Corolla 1.8: Common faults & known problems

Common faults & known problems

5 known faults documented in workshop bulletins. Of these, one concerns the engine and fuel system and one the electrical and ignition. Symptoms, causes, repair steps and part numbers are shown where supplied.

Technical specifications

Engine & fuel system

1 documented fault — symptoms, causes and workshop fixes.

Strong sulphur odour from exhaust whilst engine running

Overview

Affects: All models with 1.8 petrol engine.
Fault codes: P0420
Remedy: Software update

Symptoms

Engine malfunction indicator lamp (MIL) illuminated. Trouble code stored: P0420.

Cause

Incorrect engine management parameters due to engine control module (ECM) software fault.

Repair

Carry out electrical, mechanical and component tests (as applicable) to eliminate any other possible cause(s).
If no fault(s) found: Re-program ECM with upgraded software.

Data: Motorwise Workshop. Bulletin 3.

Electrical & ignition

1 documented fault — symptoms, causes and workshop fixes.

One or both headlamps do not operate when switched on

Affects All models.

Cause

Internal failure of combination switch.

Repair

Replace combination switch.

Data: Motorwise Workshop. Bulletin 4.

Brakes

1 documented fault — symptoms, causes and workshop fixes.

Brakes squeal

Overview

Affects: All models.

Cause

Replacement brake pads fitted without anti-squeal shims.

Repair

Ensure brake pad anti-squeal shims are fitted.
Replacement shims available separately.

Data: Motorwise Workshop. Bulletin 1.

Clutch & gearbox

1 documented fault — symptoms, causes and workshop fixes.

Squeaking noise when clutch pedal depressed or released

Affects rightHandAll models with manual transmission, →02/05. leftHandAll models with manual transmission, →03/05.Fit modified part

Symptoms

Erratic clutch pedal action. Gears difficult to engage.

Cause

Faulty clutch master cylinder.

Repair

Fit modified clutch master cylinder.

Data: Motorwise Workshop. Bulletin 2.

Other

1 documented fault — symptoms, causes and workshop fixes.

Excessive noise from auxiliary drive belt

Overview

Affects: All models with 1ZZ-FE engine code.

Cause

Faulty auxiliary drive belt tensioner.

Repair

Renew auxiliary drive belt tensioner.
Renew auxiliary drive belt.

Data: Motorwise Workshop. Bulletin 5.

Glossary

Technical terms used in this guide.

MIL: Malfunction indicator lamp — the engine warning light on the dashboard
ECM: Engine control module — the electronic unit that manages the engine
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
Trouble Code: A standardised fault code stored by a control module, read with a diagnostic tool
Auxiliary Drive Belt: The belt that drives the alternator, water pump, steering pump or air-conditioning compressor

Frequently asked questions

What are the common faults with the Toyota Corolla 1.8?

This guide contains five workshop bulletins for the Toyota Corolla 1.8. Of these, one concerns the engine and fuel system and one the electrical and ignition. Symptoms, causes, repair steps and part numbers are shown where supplied.

Does every Toyota Corolla 1.8 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 Corolla 1.8 faults myself?

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