Engine Light Codes (OBD-II for 2017 Ford Escape)

The check engine light looks scary, but a calm scan and a few basic checks solve most issues. This page shows how I read codes on a 2017 Ford Escape, what the common codes mean in plain English, and the quick tests that point you in the right direction. I follow the same routine on our Escape, which we call Alice. Always confirm repair steps in a service manual if a job goes beyond simple driveway work.

How to read and use codes the smart way

1. Scan for current and pending codes. Pending helps you catch issues that are starting to appear.
2. Open the freeze frame. Note engine temp, RPM, speed, and load at the moment the code set. That context matters.
3. Do not clear codes yet. Fix first, then clear. If you clear codes before you look, you lose freeze frame and readiness status.
4. Visual checks save time. Look for loose intake tubes, cracked vacuum lines, broken connectors, and blown fuses.
5. Test drive and re-scan. After a fix, drive through a few speeds and conditions, then check that monitors are ready and codes have not returned.

Misfire and rough running

• P0300–P0304: Random or cylinder specific misfire. Common on any engine if plugs are old or a coil boot is cracked.
  • Check first: Plug age, plug gap, coil boots for carbon tracking, loose coil connectors, vacuum leaks. On EcoBoost, also check charge pipe clamps and the air filter seating.
  • DIY path: Swap coils between cylinders to see if the misfire moves, replace worn plugs with the correct iridium part, fix intake leaks, then clear and retest.
• P0507: Idle higher than expected.
  • Check first: Vacuum leaks, dirty throttle body, sticky PCV hose or valve.
  • DIY path: Clean the throttle body gently, inspect hoses, confirm no air leaks after the MAF or MAP sensor, then perform an idle relearn if needed.

Fuel trim and air metering

• P0171: System too lean bank 1. Often unmetered air or a weak fuel supply.
  • Check first: Intake tube splits, loose clamps, vacuum hoses, PCV lines, dirty or faulty MAF (if equipped), lazy O2 pre-cat, weak fuel pressure.
  • DIY path: Fix obvious air leaks, clean the MAF with the correct cleaner, check short and long term fuel trims at idle and 2500 rpm, inspect the exhaust for leaks near the front O2.
• P0172: System too rich bank 1.
  • Check first: Leaking injector, high fuel pressure, stuck purge valve, saturated air filter from oil, failed O2 pre-cat reading rich.
  • DIY path: Inspect purge line behavior at idle, verify trims are negative, check for fuel odor in vacuum lines, and inspect plugs for wet tips.
• P0101/P0106: MAF or MAP performance.
  • Check first: Dirt on sensor, incorrect orientation, intake leaks, wiring damage.
  • DIY path: Clean sensor with MAF-safe cleaner, reseat connectors, repair torn hoses.

Turbo and boost related (EcoBoost engines)

• P0299: Turbo underboost.
  • Check first: Loose charge pipes, intercooler hose splits, weak wastegate actuator, boost leaks that leave oil mist marks.
  • DIY path: Tighten or replace clamps, smoke test the intake, inspect intercooler and hoses, clear and road test with a scanner watching boost and throttle position.
• P0234: Turbo overboost.
  • Check first: Wastegate control line issues, stuck wastegate, sensor misread.
  • DIY path: Inspect vacuum or control lines, check actuator movement, verify MAP readings are sensible.

EVAP and gas cap style problems

• P0442/P0456: Small EVAP leak detected.
  • Check first: Gas cap seating and seal, cracked EVAP hoses near the purge valve and canister, loose quick-connects.
  • DIY path: Inspect and reseat the cap until it clicks, replace a damaged cap seal, check hoses for splits, smoke test the EVAP line if you have the tool.
• P0443/P0496: Purge flow or purge valve control issues.
  • Check first: Purge solenoid sticking, wiring to the valve, vacuum present at the intake at the wrong time.
  • DIY path: Test the valve with a handheld vacuum or command with a capable scanner, replace if it bleeds when it should be closed.

Catalyst and O2 sensor

• P0420: Catalyst efficiency below threshold bank 1.
  • Check first: Exhaust leaks before the front O2, lazy O2 sensors, misfires that cooked the cat, long-term fuel trim issues.
  • DIY path: Fix any misfire or trim problem first, check for leaks at flanges and flex joints, monitor O2 waveforms if your scanner supports it.
• P013A, P015A style slow response codes.
  • Check first: Old upstream O2 sensor, wiring, exhaust leaks.
  • DIY path: Inspect and replace the sensor if age and data point to it, clear and confirm trims stabilize.

Cooling and temperature

• P0128: Coolant temperature below thermostat regulating temp.
  • Check first: Stuck-open thermostat, low coolant, inaccurate ECT sensor.
  • DIY path: Verify coolant level when cold, feel upper hose warm-up behavior, replace thermostat and seal if it warms slowly and stays cool while driving.
• P0117/P0118: ECT circuit low or high.
  • Check first: Sensor connector, wiring chafe, sensor failure.
  • DIY path: Inspect and reseat connector, repair wiring, replace the sensor if readings are implausible.

Throttle and airflow control

• P2111/P2112: Throttle body stuck open or closed.
  • Check first: Heavy carbon on the throttle plate, connector issues, mechanical binding.
  • DIY path: Clean the throttle body gently with the right cleaner, check connector pins, perform an idle or throttle relearn if needed.

When to call a pro

• Metallic turbo noises, visible fuel leaks, or overheating
• Codes that return immediately after you fix basics like air leaks, plugs, or caps
• Electrical faults that require pin-out tests and wiring diagrams you do not have

My quick workflow for Alice

1. Scan and save a photo of the codes and freeze frame
2. Visual inspection, especially intake tubing and connectors I touched recently
3. Live data check at warm idle and 2500 rpm. Watch trims, ECT, MAP or MAF grams per second
4. Targeted test or part swap if the data points clearly. No parts cannon
5. Fix, clear, drive several cycles, confirm readiness and no return

Products to buy

Links open in a new tab and already include my Amazon tag. Match fitment and specs to your exact engine and region.

Scanning and testing

• OBD-II Bluetooth scanner with live data Shop scanners
• Basic handheld code reader if you prefer a cable Shop readers
• Automotive smoke machine for intake and EVAP leak checks Shop testers
• Digital multimeter for sensor and ground checks Shop meters

Common fix supplies

• Motorcraft or equivalent iridium spark plugs, confirm part by engine Shop plugs
• Ignition coils or boot kits, verify by VIN Shop coils
• MAF sensor cleaner and throttle body cleaner, use the right type on each part MAF cleaner · Throttle cleaner
• Replacement gas cap or cap seal if yours is cracked Shop caps
• Silicone vacuum hose and quality clamps for small leaks you find Hose · Clamps

FAQ