Location of Components:
The EST system isn't one single component but a network. Key areas to inspect include:
* EST Module (Control Module): This is the "brain" of the system. Its location varies slightly by engine (TBI vs. TPI), but it's typically found near the ECM (Engine Control Module). It's a small, rectangular black box with multiple connectors. Consult a wiring diagram for your specific engine to pinpoint its location.
* Pick-up Coil (or Crankshaft Position Sensor): This sensor is crucial. It's usually mounted on the distributor (or near the crankshaft for some models). It sends signals to the EST module about crankshaft position, which is used to determine spark timing.
* Wiring Harness: The wiring connecting the EST module, pick-up coil, and ECM is susceptible to damage (broken wires, corrosion, poor connections). Check the wiring for breaks, chafing, and corrosion, particularly around the connectors.
* Power and Ground Connections: Ensure the EST module receives the correct voltage and has a good ground connection. Look for loose or corroded connections on the battery, ground straps, and the module itself.
* ECM (Engine Control Module): The ECM works in conjunction with the EST module. While a failing ECM is less likely the direct cause of code 43, a faulty ECM *could* impact the EST system.
Troubleshooting and Repair:
1. Visual Inspection: Begin by visually inspecting all the components and their wiring harnesses mentioned above. Look for obvious damage, loose connections, corrosion, or burnt wires.
2. Voltage Checks: With the ignition on, use a voltmeter to check the voltage at the EST module's power and ground connections. You should have battery voltage at the power input and a good ground (0 volts). Check the voltage at the pick-up coil's output signal wire – this may require a wiring diagram to know which wire it is.
3. Pick-up Coil Testing: Testing the pick-up coil often requires an oscilloscope (to check for the proper signal waveform), although a multimeter can sometimes give a rudimentary check of resistance. Consult a repair manual for your specific engine for the correct testing procedure.
4. Wiring Checks: Carefully examine the wiring harness for any breaks, shorts, or corrosion. Repair or replace any damaged wiring. Pay close attention to connectors – ensure they're clean and making good contact.
5. EST Module Testing: Testing the EST module itself is more involved and usually requires a specialized tool or a comparison to a known good module. Many auto parts stores can test it for you.
6. ECM Check: While less likely, a faulty ECM can interfere. If you've checked everything else and still have the code, consider having your ECM tested or inspected.
Important Notes:
* Repair Manual: A repair manual specific to your 1989 Camaro (with the correct engine type) is absolutely crucial. It will provide wiring diagrams, component locations, and testing procedures.
* Safety: Disconnect the negative battery terminal before working on any electrical components.
* Professional Help: If you're not comfortable working with automotive electrical systems, it's best to take your Camaro to a qualified mechanic. Incorrect repairs could damage other components.
This process is systematic. Start with the easiest checks (visual inspection, voltage checks) and move to more complex diagnostics as needed. Remember that a simple loose connection is often the root cause of many electrical issues.
