Ford Mondeo dashboard warning lights
Every symbol, every colour – fully explained for Mondeo Mk4, Mk5, Hybrid & ST. Our mechanics reveal common failures, step-by-step diagnosis (DIY + pro), and real-world repair costs. No fluff, just actionable data.
70+ warning lights analysed | includes OBD-II code table
Top 10 Ford Mondeo specific OBD-II codes
| Code | System | Common cause (Mondeo) | Est. repair cost |
|---|---|---|---|
| P0420 | Catalyst | Catalyst efficiency below threshold (2.0L Duratorq / EcoBoost) | $900–$2,200 |
| P0300 | Engine misfire | Ignition coil failure (known on 1.6 EcoBoost) | $200–$600 |
| P2196 | O2 sensor | O2 sensor stuck rich (often after cold start) | $250–$450 |
| P0087 | Fuel rail pressure | Low pressure – HPFP or sensor (2.0 TDCi) | $600–$1,500 |
| U0100 | Lost comms ECM | ECU power or ground issue (water ingress in passenger footwell) | $400–$1,200 |
| P0401 | EGR | EGR insufficient flow (clogged – diesel Mondeo) | $350–$800 |
| C0034 | ABS | Rear right wheel speed sensor failure (common) | $150–$270 |
| P2002 | DPF | Diesel particulate filter efficiency below threshold | $700–$2,500 |
| P0299 | Turbo | Turbo underboost (leaking hose or VNT stuck) | $400–$1,100 |
| B1318 | Battery | Low battery voltage – often after stop-start | $150–$300 |
Scroll table horizontally on mobile →
⚠️ Check Engine Light (MIL)
OBD-II / PCMIssue & symptoms
- Common issues: O2 sensor (P0135), EVAP leak (P0455), MAF, coils (P0300-P0304).
- Symptoms: Rough idle, poor acceleration, increased fuel consumption, or no change.
Diagnosis (step by step)
- 1. Read codes with OBD-II scanner – note pending and permanent codes.
- 2. Check freeze frame data (RPM, temp, load).
- 3. Visual inspection: vacuum hoses, air filter, gas cap.
- 4. For Mondeo: common coil failure on cyl 2 (Mk4 1.8).
Repair cost
Diagnostic: $80–$150
O2 sensor: $200–$400
Ignition coil (set of 4): $300–$650
EVAP repair: $150–$400
Flashing light? Stop engine – catalytic converter damage risk.
🛢️ Oil Pressure Warning
red / low oilIssue & symptoms
- Low oil level, failed pump (2.0 TDCI known), clogged pickup, worn bearings.
- Symptoms: Ticking, light flickers at idle, engine hot.
Diagnosis
- Check dipstick immediately.
- Listen for knocking – if oil ok, suspect pressure sensor (common).
- Use mechanical gauge to verify pressure.
Repair cost
Oil top-up: $10–$30
Sensor: $120–$220
Oil pump: $800–$1,600
Engine rebuild: >$3,500
STOP engine – severe damage in minutes.
🔋 Charging System
battery/alternatorIssue & symptoms
- Alternator failure (Mk5 2.0 EcoBoost), bad battery, broken belt.
- Dim lights, slow crank, “battery saver” message.
Diagnosis
- Voltage test: engine off 12.4V+, running 13.8–14.4V.
- Check belt condition, alternator connections.
- Load test battery.
Repair cost
AGM battery: $200–$350
Alternator (reman): $500–$950
Belt tensioner: $250–$450
⛔ Brake Warning
fluid / padsIssue & symptoms
- Low fluid (pad wear), handbrake switch, ABS module.
- Symptoms: Spongy pedal, screeching.
Diagnosis
- Check reservoir level, inspect pads.
- Scan ABS module codes.
Repair cost
Fluid flush: $90–$140
Pads front: $180–$350
ABS module: $900–$1,700
🛞 ABS / ESP
anti-lock / stabilityIssue & symptoms
- Wheel speed sensor (rear common), steering angle sensor, pump.
- ABS inactive, ESP off, maybe speedo dead.
Diagnosis
- Read ABS codes with advanced scanner (Forscan).
- Check sensor resistance ~1kΩ, reluctor ring for cracks.
Repair cost
Speed sensor: $120–$270
ABS pump: $800–$1,600
Steering angle sensor: $250–$450
💺 Airbag (SRS)
safety restraintIssue & symptoms
- Clock spring (horn + airbag), passenger seat sensor (Mk4), crash sensor.
- Light stays on, horn may not work.
Diagnosis
- Only SRS scanner – never use multimeter on circuits.
- Check under-seat connectors (often loose).
Repair cost
Clock spring: $200–$450
Occupancy sensor: $300–$750
Module reset: $150–$300
🔘 TPMS (tyre pressure)
sensor / low airIssue & symptoms
- Low pressure, dead sensor battery, wheel change without relearn.
Diagnosis
- Check pressures, use TPMS tool to trigger sensors.
- Mondeo often needs relearn after rotation.
Repair cost
Sensor replacement: $80–$200
Relearn: $50–$100
🌡️ Coolant overheat
red tempIssue & symptoms
- Low coolant, thermostat stuck (2.0 TDCI), fan failure.
- Steam, gauge high, heater cold.
Diagnosis
- Check coolant level (cold), inspect for leaks.
- Check fan operation with A/C on.
Repair cost
Thermostat: $200–$350
Water pump: $400–$800
Radiator fan: $350–$700
⚙️ Power steering
EPS / fluidIssue & symptoms
- Electric rack fault (Mk5), torque sensor, low fluid (hydraulic).
- Heavy steering, warning light.
Diagnosis
- Check fluid (if hydraulic).
- Scan for C1A00, C1A60 – torque sensor.
Repair cost
EPS calibration: $150–$250
Torque sensor: $400–$800
Rack replacement: $1,500–$2,800
💨 DPF (diesel)
particulate filterIssue & symptoms
- Clogged DPF due to short trips, failed regen, sensor drift.
- Loss of power, auto stop-start disabled, high oil level.
Diagnosis
- Check soot mass with diagnostic tool (>30g = clogged).
- Monitor differential pressure sensor.
- Forced regen test.
Repair cost
DPF cleaner additive: $50–$150
Professional cleaning: $500–$1,200
New DPF: $2,000–$4,200
💧 AdBlue / urea
emissions fluidIssue & symptoms
- Low level, crystallised injector, NOx sensor (frequent).
- Countdown warning (engine no-start after 0 miles).
Diagnosis
- Top up and reset – if light persists, check injector.
- Scan for P20EE (NOx sensor).
Repair cost
Top-up: $20–$50
Injector: $400–$800
NOx sensor: $350–$700
⚙️ Transmission warning
auto / PowershiftIssue & symptoms
- Powershift (DPS6) TCM failure, clutch wear, solenoids.
- Harsh shifts, slipping, limited gears, failsafe mode.
Diagnosis
- Scan TCM for codes (P07A3, P0902).
- Check fluid level (only specialist).
- Inspect wiring to mechatronic unit.
Repair cost
Fluid change: $250–$400
TCM reprogram: $200–$400
Clutch kit: $1,800–$3,200
Mechatronic: $2,000–$3,500
🔥 Glow plug light
diesel preheatIssue & symptoms
- Faulty glow plugs, relay, or control unit.
- Difficult cold start, white smoke, light flashes.
Diagnosis
- Test glow plug resistance (0.5–2Ω).
- Check relay operation with multimeter.
Repair cost
Set of 4 glow plugs: $120–$250
Relay: $80–$150
Control module: $200–$450
🛣️ Lane keep / Pre-collision
camera/radarIssue & symptoms
- Blocked camera (ice/dirt), radar misalignment, module failure.
- Warning lights, assist functions unavailable.
Diagnosis
- Clean windshield area near rearview mirror.
- Check for front radar obstruction.
- Forscan codes – C1A60, U3000.
Repair cost
Camera recalibration: $300–$600
Radar sensor: $900–$1,800
🔧 Service due / wrench
maintenanceIssue & symptoms
- Scheduled maintenance reminder (oil, inspection).
- No performance issue, just reminder.
Diagnosis
- Check service history.
- Can be reset manually or with scanner.
Repair cost
Oil change service: $100–$250
Inspection: $80–$150
General diagnosis workflow (any warning light)
- 1. Colour priority: Red = stop, Orange = plan visit, Green/Blue = info.
- 2. Scan for codes: Use OBD-II (generic) or Forscan (Ford specific).
- 3. Visual inspection: Fluids, belts, connectors, obvious damage.
- 4. Check service bulletins: Mondeo known issues (PCM updates, wiring chafing).
- 5. Component testing: Multimeter, pressure gauge, or swap known good part.
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