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.

U0100

Lost communication with ECM / PCM

urgent

The network cannot hear the engine computer. Power, grounds, or a dead ECM — start at fuses.

Likely systems

ECM power / grounds
CAN
ECM

Do not throw parts · Do not buy an ECM because it is silent. Silent is often hungry.

First look · Voltage at ECM power pins. Are other modules also silent?

Say this
I have U0100 stored. I want voltage at the ECM power pins before a computer.

network (modules talking to each other). Subsystem looks like module communication. Generic (SAE) code. SAE-generic layout. The number is real even if our paragraph is missing.

Take U0100 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

Lost communication with ECM / PCM

Do not throw parts

ELM327

Type the scanner code

Lost communication with ECM / PCM