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SRT-4 Engine Management System: Wiring the Control Unit Computerized Engine-Control Module, Part 2 of 4 From "Tricked Out" episode DTRK-308

(Continued from page 1)

	Figure E
	Figure F

Boost Control Solenoid

Now that all of the ECU wiring has been taken care of, the next step is to move on to the boost control solenoid. Since the engine is being modified to run more boost, the turbo waste gate (figure E) needs to be "fooled" into opening at higher pressures. The boost control solenoid is going to mount in the signal line that operates the gate. When the computer tells the solenoid to open, less signal pressure will get to the waste gate, it will stay closed longer, and you'll therefore get more boost and more power.

• Find a suitable location in the engine bay to mount the unit (figure F).

• Use a punch to divot the mounting holes, and install the unit with self-tapping screws.

• Attach the boost solenoid ground lead to it with an eyelet connector.

• Use a fuse tap to attach the positive lead to a switched ignition source in the fuse box under the hood.
  

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  Figure F

• The vacuum line connections in the project car are simplified with a vacuum block that was previously installed, but the hookups are the same. The line that runs to the turbo waste-gate is connected to one side of the boost controller and a new line is run to where the waste gate line was originally attached (figure G).

• After the boost control solenoid is installed, you can hook up the new map sensor. It can plug into any vacuum line port to provide pressure readings to the new computer. On this car. it can plug right into the vacuum block with the boost control solenoid.

• Cut the manifold pressure line with a pair of scissors and add a brass T-fitting to make a new port.

• Cut off a section of vacuum line suitable for the installation, and then plug one end into the T fitting, run the new line towards the fender, and plug the other end into the map sensor.

• Secure the map sensor with a wire tie, and then plug it into the boost control harness.

• After the boost control solenoid and the map sensor are installed, push the connector end of their wiring harness through the firewall grommet along with the controller end of the oxygen sensor lead.

• The other side of the oxygen sensor wire can be dropped down behind the engine for now.

• Secure all of the new wiring with wire ties and hide as much as you can with split loom.
  

  	Figure H
  	Figure I

• Inside the car, plug the sensors to the control units per the manufacturer's instructions (figure H).

• Pop of the fuse panel door to access the power supply, and run the red and black power wires from the power supply harnesses to the interior fuse panel.

• Use an eyelet connector to attach the negative lead to a solid ground point. Attach the red lead from the wideband module to a switched ignition source with a fuse tap (figure I).

• After all of the interior components are positioned, carefully remove any slack remaining in the wiring by pulling the excess wire through the firewall.

• Neaten up the under-dash wiring using more wire ties, and stow the control boxes under the trim panels.

• Replace the lower dash trim panel to finish inside.

Important: Included in this summary are the steps in this automotive procedure as shown in the episode. These steps are general guidelines that are applicable to most vehicles. With any particular car or truck, there may be procedures, specifications, settings, tolerances, components, etc. that are specific to that vehicle. There are also variations according to the type and brand of upgrade-kit you select. Always consult your vehicle's service manual when undertaking significant automotive repairs, and read and follow the manufacturer's directions and precautions that come with your kit or replacement parts.

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RESOURCES :

Design Engineering
www.designengineering.com

Howell Automotive
www.howellautomotive.com

AEM
www.aempower.com

LNS Motorsports
www.LNSmotorsports.com