OBD II Archives - Brake & Front End
The Fight For The OBDII Port

Small signs are pointing to a new war for access to vehicle diagnostics.

VIDEO: OBD II Dongles: What Your Customer Doesn’t Know Can Hurt Them

Jason Stahl discusses OBD II dongles, typically used by customers to diagnose their own vehicles, and how they can interfere with important communications channels in the vehicle’s systems. Sponsored by Standard.

VIDEO: OBD2 TPMS Relearn Advantages

Andrew Markel discusses TPMS relearn through the OBD2 port, and its advantages over some of the mechanical methods elsewhere on the vehicles. Sponsored by Bartec.

Matco Tools Offers MAXTPMS And OBD II Module

This unit was designed to bypass many of the manual reset procedures that are time consuming and confusing for domestic and import vehicles.

Oxygen Sensors: Pulse Measurement

Watching an oxygen sensor output on an oscilloscope is like watching a sporting event on television. You get to see the action, but can do nothing about it as it happens. Sometimes you miss the action and want an instant replay. It was a bad call. You saw the interference. If the referee didn’t see

oxygen sensors
OBD II Misfire And Diagnosis

When diagnosing misfires, it’s important to use tools that allow you to go beyond a simple code reader that displays a P03XX. Even an OEM-level scan tool can’t tell you what the firing voltage is or what the ignition pattern looks like. Nor can it tell you if the serial data is accurate or correct. For that kind of information you need a DVOM or a graphing multimeter/oscilloscope that can look at sensor voltages directly and display primary and secondary ignition patterns.

ASE L1: Understanding Scan Tool Modes

Section B, Item 8 of the ASE L1 certification task list states:
“Interpret OBD II scan tool data stream, diagnostic trouble codes (DTCs), freeze-frame data, system monitors, monitor readiness indicators, and trip and drive cycle information to determine system condition and verify repair effectiveness.” What ASE is talking about are the modes of OBD II scan tool protocol. Modes are usually denoted by a dollar sign and a two-digit number.

Catalytic Converters: Replacement Is Changing

If your shop is not in California, the replacement of the catalytic converter is simple and typically there is only one replacement option. Most shops understand that they must replace the converter and that using a test pipe or bypassing the converter is bad for business and against the EPA regulations and could result in big fines.

Tech Tip: Fuel Filler Necks And Related Check Engine Light Conditions

Since the introduction of the OBD II system, manufacturers have continued to improve on the monitoring of evaporative emissions, with the complete evaporative system being under a scrutinized surveillance. Codes like P0440 to P0456 are all related to the fuel vapor control, including leaks.

Tech Tip: Every MAF Sensor Needs a Breath of Fresh Air

Sensor replacement is critical to engine efficiency because a dirty MAF sensor will not respond as fast to air flow changes as a clean sensor.

Tech Tip: Hyundai Has Check Engine Light On with Fuel System Lean Code

The check engine light is on with a post catalyst fuel system lean code P2096, an oxygen (O2) sensor stuck lean B1/S2 code P2270, and an O2 sensor no activity B1/S2 code P0140.

Tech Tip: Chrysler Vehicle (300/Magnum/Charger) Has Multiple DTCs Set, MIL Illuminated

This bulletin involves repositioning the upstream oxygen (O2) sensor connectors and replacing the wiring harness connector(s) and O2 sensor(s) as necessary.