What causes ECU no communication?

What causes ECU no communication?

With error message showing “No-Communication”! In most cases, communication issues can be caused by various reasons including: ignition-key position, connector-voltage issues, incorrect communication protocol, hung ECM, missing or bad data, and OEM-updated ECM software that is unknown to the scan tool.

What is OBD communication failure?

If the cigarette lighter fuse is burned out, the vehicle will not communicate with the test equipment during the OBD inspection. The fuse is faulty if it is dark inside like the inside of a blown light bulb or if the electrical wires within the fuse are burnt apart and not connected.

Where is the OBD fuse?

One under the hood, one in the trunk and another behind the dashboard. The OBD fuse may be listed on the fuse cover as OBD II, DLC, Accessory port, 12 v power point or cigarette lighter and will most likely be located inside the vehicle. The most efficient way to locate it is check the drivers manual.

How do I know if my ECU is fried?

Here are the most common symptoms of a bad ECU:

  1. Check Engine Light stays on after resetting.
  2. Car was jump started on reverse polarity.
  3. Engine turning off for no reason.
  4. Water Damage or Fire Damage on the ECU.
  5. Apparent loss of spark.
  6. Apparent loss of injection pulse or fuel pump.
  7. Intermittent starting problems.
  8. Overheating ECU.

How do you know if your ECU is faulty?

The main symptoms of a faulty ECU Well-known examples are: engine failure light (MIL light) that lights up on the instrument cluster, car that goes into emergency mode, the car shakes or when the engine no longer runs on all cylinders. It can all indicate a malfunction of the engine control unit.

What does OBD system check mean?

OBD systems are designed to alert drivers when something in the engine or emission control system begins to deteriorate or fail. When the OBD system determines that a problem exists a code is stored in the computer memory. The computer may illuminate a dashboard light indicating “Service Engine Soon” or “Check Engine.”

Which fuse controls check engine light?

The fuse that reins the check engine light is akin to the small yellow box-like item situated on the lower-left corner, with two 10mm fuses. It’s a double fuse on the fuse box beneath the dash and reads ROOM/PLAFON.

What to do if the OBD II scanner doesn’t communicate with the vehicle?

What to do if the OBD II scanner doesn’t communicate with the vehicle. TEST 1: Connect the positive DMM lead to DLC pin 4 and the negative DMM lead to the negative battery terminal, using jumper wires if necessary. Do not connect to the body or chassis ground but to the battery terminal directly.

What is the code for Crank no start?

Come along with Eric O. at the SMA shop as he has a look at this 2009 Chevrolet 1500 5.3 that was towed in as a crank no start. It has a code stored in it U0109 for “loss of communication with fuel pump control module.” You can follow along with Eric O. as he brings you along and diagnosis the FPCM.

Why is my HPFP VCV not communicating with OBD?

The fact that you can’t communicate over OBD at all is concerning. You might need to setup a scope and see what the HPFP VCV is doing, if no fuel is coming I’d start tracking that down. Might want to check your CAS or the junction box electronics.

How to communicate with DME with no cranks?

Car acts totally normal, lights come on, everything is good… click ignition button on, pump primes and never goes off, water pump can be heard turn on, clicking in engine bay just like normal when ON is pressed, car cranks strong… no start, no fuel smell. Cant communicate with DME via known good MHD and OBD2 Blutooth w/Torque

What does no start no crank no click mean?

If you have a late model GM vehicle and turn the key only to hear nothing, you’ll most likely think you have a dead battery—and you may. But a no start, no crank, no click condition can be far more involved than that. In the old days, power flowed through the ignition switch and down to the starter solenoid. Not anymore.

What to do if the OBD II scanner doesn’t communicate with the vehicle. TEST 1: Connect the positive DMM lead to DLC pin 4 and the negative DMM lead to the negative battery terminal, using jumper wires if necessary. Do not connect to the body or chassis ground but to the battery terminal directly.

What is a typical GM starting system wiring diagram?

Click on the image here to pull up a PDF of a typical GM starting system wiring diagram. Depending on the year, model and engine of your GM vehicle, your starting system may be less complicated or use only some of the components shown here. For example, earlier anti-theft systems didn’t communicate the same way with the PCM.

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