🚗 Every symbol, every color – what your ASX is telling you. From a simple reminder to an imminent breakdown, this guide covers issues, symptoms, multiple diagnostic methods, and real-world repair costs for petrol, diesel, and 4WD variants. Bookmark this page for the road.
Check Engine (MIL)
amberEngine, emission, or sensor fault. Common: loose fuel cap, O₂ sensor, catalytic converter, ignition coil, MAF sensor, EVAP leak.
Steady or flashing light; rough idle, misfire, poor acceleration, increased fuel consumption, failed emissions test.
- Method 1: Check fuel cap – tighten, drive 2–3 days (light may reset).
- Method 2: OBD-II scanner: read codes (e.g., P0420, P0300, P0171). Free at many auto parts stores.
- Method 3: Visual inspection – vacuum hoses, air filter, wiring harness damage.
- Method 4: Professional smoke test (EVAP leaks) or compression test (mechanical).
- Method 5: Live data monitoring (fuel trims, O2 sensor voltages) to pinpoint failing component.
Oil Pressure
redLow oil level, worn oil pump, clogged filter, pressure relief valve stuck, or faulty sensor.
Light flickers at idle, stays on while driving; engine ticking, knocking, or overheating.
- 1. Park level ground, check dipstick – top up if low.
- 2. Listen for engine noise – stop immediately if knocking.
- 3. Manual oil pressure gauge test (mechanic attaches to sender port).
- 4. Inspect for leaks (oil pan, filter, drain plug).
- 5. Replace oil and filter (if overdue).
Battery / Charging
redFaulty alternator, broken serpentine belt, bad battery, corroded terminals, parasitic drain.
Dimmer headlights, slow crank, “click” when starting, warning light flickers, electrical failures.
- 1. Check battery terminals clean/tight.
- 2. Multimeter: engine off 12.4V+ ; running 13.8–14.8V (if <13.5V, alternator weak).
- 3. Load test battery (free at parts stores).
- 4. Inspect serpentine belt for cracks or looseness.
- 5. Parasitic draw test (ammeter) if battery drains overnight.
Brake Warning
redParking brake engaged, low brake fluid, worn pads, ABS fault, brake booster failure.
Light stays on, spongy or hard pedal, increased stopping distance, squealing.
- 1. Release parking brake fully.
- 2. Check brake fluid reservoir level – top up if low.
- 3. Inspect for leaks (calipers, wheel cylinders, lines).
- 4. Measure pad thickness (through wheel spokes).
- 5. Scan ABS module if light flashes or combined with ABS light.
ABS
amberWheel speed sensor failure, damaged tone ring, ABS pump/module fault, blown fuse.
ABS inactive (normal braking works), light on, possible traction control light also on.
- 1. Read ABS codes with advanced scanner (generic OBD-II may not show ABS).
- 2. Inspect wheel speed sensors for dirt, damage, or loose wiring.
- 3. Check tone ring (teeth) for cracks or missing teeth.
- 4. Fuse check under dash/hood.
- 5. Test sensor resistance with multimeter (typically 1k–2k ohms).
Airbag (SRS)
amberFaulty clockspring, passenger seat occupancy sensor, crash sensor, or module communication.
Airbag warning stays on; airbags may not deploy in crash; passenger airbag off light may behave erratically.
- 1. SRS-specific scanner required (dealer or high-end scan tool).
- 2. Check under-seat connectors (yellow) for corrosion or looseness.
- 3. Recall check for ASX (Takata airbag recalls).
- 4. Never use multimeter on airbag circuits – risk of deployment.
Tyre Pressure (TPMS)
amberLow pressure, sensor battery dead, sensor damaged, or TPMS module fault.
Light on solid or flashing; warning message “tyre pressure low”.
- 1. Check all tyre pressures with gauge, inflate to spec (usually 33–36 psi).
- 2. After inflation, reset system via button (under dash left) or drive above 25 mph for 10 min.
- 3. TPMS trigger tool to wake sensors and read IDs (if available).
- 4. If light flashes 60–90 seconds then stays on: sensor fault/dead battery.
Coolant Temp
red/amberOverheating, low coolant, faulty thermostat, water pump failure, radiator blockage, cooling fan inoperative.
Gauge in red zone, steam from bonnet, heater blows cold, coolant smell.
- 1. Stop engine immediately if red. Wait to cool, check reservoir level (when cold).
- 2. Look for leaks: radiator, hoses, water pump weep hole.
- 3. Verify cooling fan operation (should run when AC on or engine hot).
- 4. Pressure test cooling system (tool from auto store).
- 5. Check thermostat: open/close test in hot water.
Power Steering (EPS)
amberElectric motor fault, torque sensor, wiring issue, low battery voltage (EPS shuts off to save power).
Heavy steering, intermittent assist, light on, sometimes steering wheel vibration.
- 1. Check 12V battery condition and charge – EPS is sensitive to voltage.
- 2. Scan EPS module (dealer or high-end scanner) for codes.
- 3. Inspect wiring around steering column for damage.
- 4. Torque sensor calibration may be needed.
ASC / Stability
amberSteering angle sensor, yaw rate sensor, accidental deactivation, or ABS-related fault.
Light steady (system off) or flashing (active intervention). Traction control may be disabled.
- 1. Check if ASC button was pressed (light may indicate system off).
- 2. Read ABS/ASC codes (shared module).
- 3. Recalibrate steering angle sensor (with scan tool).
- 4. Check wheel speed sensor data for plausibility.
Glow Plug (Diesel)
amberOne or more glow plugs failed, relay defective, wiring harness burnt (common on 4N14 engine).
Light stays on after engine starts; hard starting in cold weather, white smoke on startup, rough idle until warm.
- 1. Check glow plug resistance (multimeter between terminal and engine ground – should be <1 ohm).
- 2. Test voltage at plug during pre-glow (ignition on) – should be battery voltage.
- 3. Inspect glow plug harness for melting (common).
- 4. Relay click test.
AWD / 4WD
amberTransfer case oil temperature high, AWD coupling unit fault, wheel speed mismatch, differential lock issue.
Light on, AWD temporarily disables (FWD only), message “Service AWD”.
- 1. Check for oversized tyres or different pressures – can trigger speed mismatch.
- 2. Scan AWD/4WD module for codes (e.g., C1023, C1045).
- 3. Inspect transfer case fluid level and condition.
- 4. Check AWD coupling relay/fuse.
DPF (Diesel)
amberDPF clogged due to frequent short trips, failed regeneration, differential pressure sensor fault.
Light on, limp mode, reduced power, increased fuel consumption, automatic regeneration may not complete.
- 1. Check DPF soot load with scanner (should be < 80%).
- 2. Forced regeneration (dealership or diagnostic tool).
- 3. Check differential pressure sensor readings.
- 4. Inspect exhaust temperature sensors.
FCM / LDW
amberCamera blocked (dirt, ice), radar misalignment, sensor fault.
Warning light, system inactive, message “Forward Collision Mitigation unavailable”.
- 1. Clean windshield area around camera (behind rearview mirror).
- 2. Check for aftermarket windscreen replacement (needs calibration).
- 3. Scan for codes (dealer only).
- 4. Radar alignment (special tool).
How to diagnose any warning light – professional step-by-step
- 1. Identify symbol & color – refer to owner’s manual (available online).
- 2. Note behavior: steady, flashing, intermittent, when does it appear (cold start, acceleration)?
- 3. Basic checks: fluid levels (oil, coolant, brake), tyre pressures, battery terminals.
- 4. OBD-II scan (generic) – for engine-related lights. For ABS, airbag, etc., use advanced scan tool.
- 5. Visual inspection – wires, hoses, connectors, signs of leaks, corrosion.
- 6. Component testing – multimeter (voltage, resistance), pressure gauge, vacuum pump.
- 7. Freeze frame data – captures conditions when fault occurred.
- 8. Consult service bulletins (TSB) – known issues for ASX (e.g., glow plug harness, TPMS).
- 9. Professional diagnosis if you can’t resolve – many shops offer $100 diagnostic fee.
