ECM/PCM Archives - Page 4 of 10 - UnderhoodService
Tech Tip: Volkswagen MIL is On, with DTCs P0087/P1093 or P2293

The MIL is on, with DTC P0087 (Fuel Rail/System Pressure Too Low), P1093 (Fuel Trim 2, Bank 1 Malfunction) or P2293 (Fuel Pressure Regulator 2 Performance) stored in the ECM’s fault memory. This could be caused by excessive wear of the intake camshaft lobe that drives the high-pressure fuel pump. The wear limits maximum pump piston lift, causing fuel rail pressure fluctuations. The wear on the camshaft lobe can also lead to wear on the base of the high-pressure fuel pump cam follower.

Tech Tip: Nissan MIL On, DTC P0603 – ECM Power Supply

If you have a vehicle with the MIL on that has a DTC P0603 stored in the ECM, perform the diagnostic steps in this bulletin first.

Tech Tip: Tacoma’s MIL Is On with DTC P0705 Set

Some 2005-’09 model year Toyota Tacoma vehicles may exhibit an MIL On condition with DTC P0705 (Transmission Range Sensor Circuit Malfunction [PRNDL Input]) stored.

Tech Tip: Ford Traction Control Light On/No DTC, or DTC P1889

Some 2005-’07 Five Hundred, Freestyle and Montego vehicles equipped with all wheel drive (AWD) may exhibit the traction control warning lamp on.

Diagnostic Dilemmas: The Diagnostic Tail Gunner – Surviving in the Age of Information

One of the first survival skills my professor taught is called “preparatory set,” which is simply the act of preparing to do something. Each of us engages in preparatory set when we open our toolboxes each morning. The very act of opening our toolbox signals to our mind that we’re ready to go to work and deal with the day’s issues.

Tech Tip: Kia Has Intermittent MIL On with No Fault Code Stored

In affected vehicles, an intermittent short to ground in a circuit only intended for testing purposes may cause the MIL to illuminate and a DTC P1330 (Spark Timing Adjust) to be stored. As soon as the fault disappears, the MIL may turn off and the fault code can also be immediately erased by the engine management system, making it hard to diagnose the concern.

Pulling Codes: The Story of U1016

This Pulling Codes article will center on issues involving the powertrain control module (PCM) talking to your scan tool. In many states, this is the controller our scan tool needs to talk to in order to determine if the correct number of monitors has run and passed. It’s interesting to note that there appears to be two modes of failure in terms of communication.

Diagnostic Dilemmas: When Over-Voltages Electrocute PCMs

During the past nine months, I’ve had three instances of powertrain control module (PCM) failures on Jeep Wrangler vehicles that were evidently caused by an over-voltage condition. The first case involved an owner who requested that a local shop replace the fuel pump because his 1998 Wrangler was slow-starting in the morning. The shop found the pump pressure was marginal and replaced the pump. Because the Jeep still had the problem, the owner complained about the fuel pump, first to the shop and then to the local jobber supplying the pump.

Tech Tip: Nissan DTC P0420 Stored in ECM

If you confirm DTC P0420 (Catalyst System Efficiency Below Threshold) is stored in the ECM, determine if this bulletin applies by checking the ECM part number.

Tech Tip: Nissan’s Engine Idle Speed is 25 RPM too High

If you confirm the idle, in Park or Neutral, is more than 25 rpm above specification (with the engine warm), and/or DTC P0507 (ISC System) is stored, this incident may be the result of recent cleaning or replacement of the throttle body. The vehicle “in-use” learned idle may be higher after throttle body deposits are reduced (by cleaning or replacement).

Ford Reflash Tech Tip: PC Settings

So, you’ve just finished up a Ford, and you’re about to try and start it up. However, it needs programmed. You’ve decided to use a J2534 tool, but there are certain things you’ll need to consider before purchasing that subscription at www.motorcraftservice.com.

Gonzo’s Toolbox: Second Guessing a Second Opinion

Who out there knows everything about automotive repair? Who out there has seen it all, and wouldn’t be surprised if something so common to do now turns out to be not so common? Well, one thing is for sure, it is not me. I learn something new about this crazy car business every day. Especially when it comes to the electronics in today’s cars.