Now fuel injection is all that comes from new vehicle factories and EFI engine swaps into older vehicles are very common. It seems for many people that the scariest part of the modern engine swap is the wiring harness. These are mainly battery voltage, switched ignition voltage, PCM output to control fuel pump, and a brake switch signal for electronic torque converter control if used. We have found LT1 Swap lt1swap. Brendan Patten runs the site and is an expert on programming many of the GM multiport injection systems.
There are companies that outright sell new harnesses for LS engine swaps, and some vendors will also rework a used harness for a fee. However, with a dozen or so hours of work and your attention to detail, you should be able to rework your donor harness yourself with some basic tools.
This story is meant to give you an idea what tools and techniques are involved as we show you some work from our Chevy Tahoe harness for a 5. The process for other GM engine harnesses is similar. While it is possible to reuse a fuse block from the donor vehicle, they are often much larger and more complicated than necessary just to serve for this engine harness.
What are needed are typically four power fuses and two relays to complete the standalone harness. Understand that this harness is just for engine control and does not necessarily tie into the rest of your vehicle harness. Such outputs as the speed sensor can be used to drive an aftermarket electronic speedometer and an engine rpm signal that can run a tachometer.
Plus, today there are tablet apps that can read the OBD-II port data and display some gauge information. The earlier LS engine models were all drive-by-cable; that is, they used a traditional mechanical throttle cable. Next came drive-by-wire DBW versions that use an electronic gas pedal assembly and a servo motor mounted to the throttle body that operates the throttle plate. DBW systems on third-generation engines require you to use the gas pedal assembly and a separate throttle actuator control TAC module in addition to the PCM.
These components must be fairly closely matched by year to work properly. In most cases, it is most reliable to use components from the same year and type vehicle. In fact, pulling the engine and all related electronic components from a complete donor vehicle ensures that you have system-matching parts that will play well together.Below are the ECM Connectors for vortec 5. Should be similar for 4. Note: Removing all of these will result in a non-emissions friendly harness. If requirements are for 4 oxygen sensors, EVAP system, then you will not want to remove those components.
J1 Connector or X1. Not Used. Brake Switch Signal. Open when NOT on the brakes. Low Reference 4. Fuel Level Sensor Signal - Primary. Accessory Wakeup Serial Data. X C1. Fuel Tank Pressure Sensor Signal. X C4. X C6. X C2. X C3. Fuel Pump Relay Control - Primary. Fuel Pump Relay Control - Secondary. Starter Enable Relay Control.
X C5. Powertrain Relay Coil Control. X A7.Because Novak has always maximized our domestic supply and internal manufacturing paradigm, we are seeing little interruption due to the Co-Vi situation. However, permit a day or two extra for fulfillment and be aware that we may contact you with questions or options on items where our suppliers may be having difficulties.
One of the most significant things an installer can do to speed the conversion process along and keep the headaches at bay is to have their factory GM harness simplified and modified.
Novak has gotten this wiring process and PCM programming down to a science. Typically, the conversion installer will get the factory engine harness from the donor vehicle. Novak can simplify this harness, removing unnecessary circuits, consolidating circuits, rerouting and labelling for a simpler wire hookup into any Jeep.
Make sure your PCM and harness are compatible, if they were not pulled from the same vehicle. Intermixing PCM's and harness can yield unexpected results. Always consult us on this before moving forward. If time is of the essence, contact us.
Please note that if your PCM or its wires are damaged or in need of repair before it can be used, you may incur an up-charge for the additional labor.
Need a cool way to attach your PCM to your Jeep?
Our PCM mounting bracket assembly is the best thing to come along in this area for some time. Please do not send anything other than the harness with your shipment. We do not need the throttle pedal, fuse box, battery terminals, or any other sub harnesses, just the engine wiring harness.
If you are not sure if it is part of the engine or GM chassis harness, send it and we'll discard as necessary. Make sure to let us know your phone number and e-mail address when ordering.
The Novak shopping cart will ask for these details. We are likely to call or e-mail you with any questions and confirmations. Please contact our sales staff for accurate lead times. Jeep Dana Model T90 to the Emissions Fuel Economy Conversions, Rules vs. Welcome Guest: Login or Register. Remove VATS, calibrate to tire size, axle ratio, add upd. Add Another Option. Eliminate EGR. Eliminate EVAP. Delete brake fluid level sensor. Model- Year- VIN.Gen IV engine controller identification. The E40 controller was used on the LS2 engines exclusively.
It is identified by its three connectors, a 56 pin blue and gray and a 73 pin black. Not to be confused with the E67 ecm which has two 73 pin connectors black and gray. The distinctly larger pins is the grounds for the ecm.
The E38 controller is used on the and later truck line equipped with the 4. It is noticeable different in that it has two connectors, 73 pin black, and a 80 pin gray.
The E67 controller is used on the V6 and V8 car line starting in Next to the E38, it will be by far the most common Gen IV you will see. It is noted by three connectors which is 56 pin blue, and two 73 pin black and gray connectors.
The different slotted dividers on each connector makes it virtually impossible to make a wrong connection. A major difference on the Gen IV engines, is the use of a separate controller for the automatic transmissions. Shown here is the T42 controller, used only with the 4 speed automatics 4L60, 65, 70E. It is a 49 pin connector, the large pin is the ground. The 6 speed automatics use the T43 controller which is located in the transmission pan.
These are known as TCM's transmission control modules.Here is some helpful information if you want to modify your stock truck wiring harness your self This junction block is part of the main engine harness, that screws into the bottom of under-hood fuse block. If you want to use the whole fuse block you can, but I like to keep it clean, and wire a lot of these together.
There are a lot of wires here. Each injector has its own power wire all the way to this block. All 8 of them can be wired together into a single fuse to clean things up. This is what is done inside the fuse block. Be sure to look at the pictures of the harness at bottom of this page.
That is all to get a much cleaner look, and to simplify things later on if you have to troubleshoot anything. Provide fuel pressure to the rails, turn engine over with starter, and it will run! This would be the most basic simple way to run. There are signals for brake switch, tow haul, all of which are found in the connectors near the fuse block connector.
I don't recommend just combining all the pink wires into one and powering it. You are asking for issues if there is ever a short, including melted wires, fire, so on. Click for info. Oxygen Sensor types information - Page about the different o2 sensors used, differences in wiring, and function.
Pinouts, Pictures, Video! You can also download this in a PDF printable file with all my notes.
Thanks Paul C. Low Quality 3. Now adding videos to my YouTube channel. There will be more to come.Note: Removing all of these will result in a non-emissions friendly harness. If requirements are for 4 oxygen sensors, EVAP system, then you will not want to remove those components. Click Here!
Truck 4. Wire Color. Circuit No. LT GRN. Fuel Injector 3 Control. Fuel Injector 2 Control. Not Used. LT BLU. Knock Sensor 2 Signal. CKP Sensor Signal. Requested Torque Signal NW7. DK BLU. Ignition 1 Voltage.
Battery Positive Voltage. Crankshaft Position Sensor Ground. Low Reference. Fuel Injector 1 Control. Fuel Injector 6 Control. Starter Enable Relay Control. Fuel Injector 7 Control. Fuel Injector 4 Control.
ECU Connector Kits
Knock Sensor 1 Signal. Low Reference MAP.Shown below is Silverado diagnostic link connector DLC diagram describing how it works. As you can see here, only four 4 DLC pin terminals are used. Please review the details below. Note: Green lines above are all class 2 bus wires connected between DLC terminals and splice bar modules.
You can get this exact wiring diagram from your local parts stores or get it online from ATS. Precaution before using this diagram:. This is only an approximate diagram as I see it. Some modules and fuses were omitted to simplify the diagram. I don't profess that all of these information are correct but in case you find some errors, please contact me at my ATS homepage.
This method required a lot of wiring harness between those two modules including the sensors and other body parts. Use numerous modules or multiplex grouped together by two splices as shown above. This design NOT only save costs but it allows cheap upgrades by merely adding new modules to the circuit.
Pin 2 is the circuit main data bus wire link. It's like the communication "messenger" between all the modules used in the vehicle. Communication is also rated by speed and this model year is called Class 2 serial data bus protocol, it is thought to be slow when compared to models.
To make this diagram simple to understand, please concentrate on the wiring flow rather than the complex computer terms here. Take note also about the two 2 splices that are used here: on the left splice 1 you have the more dominant modules whereas on the right splice 2 are the modules that follow only.
The follower modules also have to pass thru a relay shown in green box. Pin 2 data bus signal wiring should read volts depending on the speed of the data bus used.
I normally use 5 volts at KOEO for slower class 2 serial data bus voltage. Pin 4 ground circuit should read zero volt or no higher than 0. Pin 5 ground circuit should read zero volt or no higher than 0. Pin 16 is power supply and should read 12 volts all the time. Above test is done using a digital voltmeter with negative lead connected to battery negative and positive lead probing the above terminal pins.How to Take Apart a PCM ECM Connector Plug 4.8L 5.3L 6.0L LS1
You can also do the same test by probing Pin 5 against Pin 2 when testing the data bus voltage or probe Pin 5 against Pin 16 to test the power supply voltage in the data bus circuit.
If you get 7 volts, it is being pulled up by a short to power. Now transfer your voltmeter positive lead to pin M red dot at Splice 1. If you have 7 volts there, unplug the BCM to see if voltage changes. Do this also one at a time with ECM at pin B red dot then followed by S2, S3 and S4 red dots at splice 1 until the voltage goes back to normal 5 volts.
There are 3 possible serial data bus speed voltage used in vehicles: 5 volts, 7 volts and 12 volts. These are the voltage readings at KOEO. With ignition key off, voltage should drop to zero. Since we are talking GM Class 2 serial data bus protocol here, it is normal to find 1. Using Isolating Class 2 serial data bus modules:. If you only suspect it is splice 2 modules only, disconnect pin blue dot top X of splice 1 and all modules and relay are isolated in splice 2.
The exact location of the splice bars splice 1 and 2 including the colors of the bus data wires are shown in detail if you have the specific wiring diagram of your vehicle.
To test each modules before replacing them: Check the tightness and integrity of each wire connections in the plugin terminals of the culprit module.
GM E39 / E39A ECM Programming Harness
If loose or not plugged in properly can cause intermittent problem. Using the power and ground distribution boxes wiring diagram, you can find which module has shorted wires. Note for module isolation: Disconnecting B red dot in splice 1 will isolate the ECM from the data bus circuit.