How to diagnose a bad engine control module?

How to diagnose a bad engine control module?

For step 4 of you diagnosing your Engine Computer, we’re gonna be covering the Process of Elimination. When diagnosing you Engine Computer by process of elimination, we are going to be focusing on two halves: the Inputs vs the Outputs. The Inputs consist of your Battery, the Ignition Switch, the Fuses, and the Sensors.

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 are the symptoms of a bad ECM computer?

There are a few things that can tip you off that there’s a problem. Here are the four most common symptoms of a bad ECM computer: There are many reasons your Check Engine light can turn on. These range from emissions problems to faulty O2 sensors to problems with the ECM.

How to diagnose an engine computer ( PCM )?

2 1. Visual Inspection 3 2. Swap 4 3. Using a Scanner 5 4. Process of Elimination 5.1 For More Information, visit our Website https://www.fs1inc.com/ or Call Us Now at 516-766-2223. Today we’re gonna be covering 4 steps to help you diagnose your Engine Computer (PCM/ECM/ECU Control Module) as to whether or not it is the issue in your vehicle.

Why is my OBD scanner not working on my GMC Sunfire?

Check your fuses, I can not remember exactly which one,but I have seen multiple times that the OBD port fuse is blown. I know some smaller GM’s (cavaliers, sunfires) are run off the electric seat fuse. The yuppie speaks the truth. Don’t ask me why GM put the OBD port on that circuit……Pull the cover and swap a fuse in that spot.

Where is the fuse for the OBD port?

I haven’t checked to see what fuse exactly, but normally a fuse for either the cig lighter, aux outlet or radio tie into the OBD ports power as well. would that fuse be in under hood fuse box? or side of dash inside the truck? I looked at the fuse list in manual, but did not see anything about obd… Thanks a lot! I’ll try and give a look soon.

Is the diagnostic reader on my GMC truck working?

When I owned my last truck and it started idling roughly, I invested in a handheld diagnostic reader. These little machines aren’t cheap, and the problem I’m now having is pissing me off.

Why is my OBD scanner not recognizing my Truck?

Every time I plug it into my CPU port, it doesn’t recognize my truck. I tested it on my friend’s 2007 Accord, and it worked fine. I’ve been troubleshooting and I can’t figure out why my truck isn’t recognized.

Where is the Keyless Go unit in the trunk?

First, we investigate the Keyless Go module which is in the trunk. To our surprise, we notice water in the spare tire well, next to the Keyless Go control unit. Even though there wasn’t that much water, every time you accelerate the water was splashing on the Keyless Go module.

Where to go to troubleshoot a body control module?

The only drawback to taking it to an auto parts store is that, most of the time, the person performing the diagnostic test can’t read the code and will refer you to a dealer, anyway. Taking your car to the dealer or other certified mechanic is always your best bet.

How can I test on the Powertrain Control Module?

To find the exact operational procedures for your device, consult your device’s handbook. Place your key into your vehicle’s ignition and turn the electrical system on. Your scanner may also need the engine running as well.

First, we investigate the Keyless Go module which is in the trunk. To our surprise, we notice water in the spare tire well, next to the Keyless Go control unit. Even though there wasn’t that much water, every time you accelerate the water was splashing on the Keyless Go module.

What do you need to know about Das key replacement?

When the replacement key is first used in the vehicle, DAS will disable the use of the key using the same key number and the previous segment. For example, if key number 2 is lost, the technician orders a replacement for key number 2 and the PDC supplies key number 2, segment 2.

What kind of ignition key does das 3 use?

Version 3 almost exclusively uses a tapered fob key with an infrared interface and has no metal blade for the ignition switch. The exception is that MY2002+ W163’s use DAS 3, even though they retain the rectangular fob and metal blade ignition key.

What do you need to know about the Das System?

It connects to the OBDII port and communicates over the CAN. FDOK – MBZ worldwide database that contains all information about ever MBZ ever built, including the assignment of all electronic key codes for all vehicles using DAS. PDC (Parts Distribution Center) – MBZ locations where parts are stored.

The best way to diagnose an engine control module fault is to understand its main responsibilities. Once you are aware of these primary functions, it becomes easier to determine what symptoms are bad PCM symptoms.

When do you have a bad Powertrain Control Module?

If you are getting codes for a faulty oxygen sensor, for example, and you have replaced all the related components but the check engine light remains illuminated, then you may have a bad PCM. The ECU is responsible for many areas of the vehicle that control whether or not the vehicle starts.

How can I find out if my engine ground circuit is bad?

There’s some unwanted resistance in the ground circuit. To locate the problem, continue with the next steps. Move your meter’s red lead to the main ground terminal, engine end side. Have your assistant crank the engine while you take a voltage drop reading.

What to keep in mind when troubleshooting ground connections?

Here are a couple of important points to keep in mind when troubleshooting grounds in your vehicle: When checking ground connections, make sure the terminals attach to a non-painted surface. You want to connect to bare metal.

How to troubleshoot Ground Control 3.0 troubleshooting guide?

GROUND CONTROL 3.0 TROUBLESHOOTING GUIDE Auto Level Sequence 1. Front landing gear retract, lowering the front of the unit below level, stopping, then lifting the front end to level the unit front to back and left to right. (Fig. 7A). 2. Rear leveling jacks are grounded (Fig. 7B). 3. A side to side leveling sequence occurs.

What are the symptoms of a bad engine control module?

1. Check Engine Light Turns On 2. Engine Stalling or Misfiring 3. Engine Performance Issues 4. Car Not Starting 5. Poor Fuel Economy The engine control module (ECM), also commonly referred to as the engine control unit (ECU) or powertrain control module (PCM), is one of the most important components found on virtually all modern vehicles.

How is the sensor ground grounded to the engine?

The sensor ground is externally grounded to the engine, as well as to the ECU. The ECU is grounded to the engine also. We know that as the injector duty cycle increases, the average ground current of the ECU will also increase, and therefore so will the voltage drop between the ECU and the engine.

There’s some unwanted resistance in the ground circuit. To locate the problem, continue with the next steps. Move your meter’s red lead to the main ground terminal, engine end side. Have your assistant crank the engine while you take a voltage drop reading.