* Camshaft Position Sensor (CMP Sensor): This sensor, like the crank sensor, is crucial for engine timing. A faulty CMP sensor will prevent the engine from firing. It's a relatively inexpensive part to replace.
* Ignition System: This is a broad category, but it includes:
* Ignition Coil(s): A failing coil won't provide the spark needed to ignite the fuel-air mixture. Testing each coil individually is necessary.
* Spark Plugs and Wires: Worn, fouled, or damaged spark plugs or wires can prevent a spark from reaching the cylinders. Check for signs of wear, damage, or fouling.
* Ignition Control Module (ICM): This module controls the ignition system. A faulty ICM can cause intermittent or complete starting failure.
* Fuel Delivery Issues (despite the new pump): While you replaced the fuel pump, there might be other fuel system problems:
* Fuel Filter: A clogged fuel filter can restrict fuel flow, even with a new pump.
* Fuel Pressure Regulator: This regulates fuel pressure in the fuel rail. A malfunctioning regulator can lead to insufficient fuel pressure. This requires a fuel pressure gauge test.
* Fuel Injectors: Clogged or faulty injectors might not be spraying fuel properly into the cylinders. A fuel injector test is necessary.
* Security System Issues: The Cadillac Escalade's security system might be preventing the engine from starting. Check for any warning lights related to the security system or immobilizer.
* PCM (Powertrain Control Module): While less likely, a failing PCM could be the root cause. This is a more expensive and complex diagnostic.
Troubleshooting Steps:
1. Check for error codes: Use an OBD-II scanner to retrieve any diagnostic trouble codes (DTCs) stored in the PCM. These codes can pinpoint the problem area.
2. Visual inspection: Carefully inspect all ignition components (wires, plugs, coils) for any visible damage.
3. Fuel Pressure Test: Use a fuel pressure gauge to measure the fuel pressure at the fuel rail. This will tell you if the fuel pump is delivering sufficient pressure.
4. Spark Test: Test for spark at the spark plugs. A simple spark tester can be used to determine if spark is present.
5. CMP Sensor Check (if not already done): This is often overlooked but just as critical as the crank sensor.
6. Check fuses and relays: Related to the fuel pump, ignition system, etc.
If you're not comfortable performing these tests yourself, take your Escalade to a qualified mechanic. They have the tools and expertise to diagnose the problem accurately and efficiently. Provide them with the information that you've already replaced the fuel pump and crank sensor. This will save time and money in the diagnosis.
