Codes desk

Beginner · short stepsExpert · spec · code · mm

The light is a pointer. Do not throw parts.

Dictionary + likely systems. Freeze-frame before parts. P0300 is not a coil kit.

WhoAudience: Anyone with a P/B/C/U on a $20 scanner.Owners and techs who want the test order.
ClickControl: Type the code. Read the English. Stop at the inspect list.Code in the box. Optional ?code= on the URL.
SayCounter: P0420 is not automatically a converter. What test first?Freeze-frame first. Then the circuit test. Then parts.

Codes · 270 in the book

Do not throw parts

Android Chrome can pull Mode 03 from a BLE ELM327. iOS Safari has no Web Bluetooth — type the code or use TestFlight native. P0420 is not a converter. P0300 is not a coil kit.

Park first · Mode 03

ELM327

Checking whether this browser can open Web Bluetooth.

P0128

Coolant thermostat — temp below range

soon

The engine will not reach full temperature. Almost always a thermostat stuck open — not a water pump and not a flush package.

Likely systems

thermostat
coolant level
ECT sensor

Do not throw parts · Do not authorize a flush as the repair unless they found rust or oil in the coolant. A flush is not a thermostat.

First look · Temperature graph to 195–210°F. Then the thermostat.

Say this
I have P0128 stored. I want a temperature graph to 195–210°F. A flush is not the repair.

powertrain (engine / transmission / hybrid). Subsystem looks like fuel and air metering. Generic (SAE) code. SAE-generic layout. The number is real even if our paragraph is missing.

Take P0128 to quote defense

The light is a pointer. Paste the RO and circle the line they hung on this code.

Do not throw parts

ELM327

Type the scanner code

Coolant thermostat — temp below range

Do not throw parts

ELM327

Type the scanner code

Coolant thermostat — temp below range