The most common cause of PROM burn-out is when the PROM is put in backwards. This will short out the PROM. It is very important that the PROM be inserted in the ECM properly to avoid this problem.
Before installing an ECM, you must test ALL related circuits on the vehicle to determine which one(s) caused the failure. Use the HOT BOX or a DVOM and measure the resistance at the harness connector. If any values are less than the specified ohms, you must find and fix the cause.
Special Note: The most common cause of ecm failure is due to one or more of the ecm controlled solenoids / relays shorted
Prior to replacing the ECM, the installer should determine what caused the ECM to fail. Common areas that cause failures are: poor grounds and powers, bad wiring, shorted solenoids/relays, or misdiagnosis by the installer.
Make sure it is fully seated. Also check for bent or broken prongs on the PROM.
QDR stands for Quad Driver. Testing the QDR’s will help pin point the cause of the ECM’s failure and prevent the same thing from reoccurring again.
The wrong ECM might have been installed. Verify the O.E. service number crosses to the correct CARDONE number.
The gear pin is designed to break to avoid damage to the cam gear and the camshaft. This problem is due to an oil pump that has seized due to insufficient oil. Inspect the oil pump. If pump does not turn freely it must be replaced.
Distributor gear and camshaft drive gear wear together in a pattern. When only one of the pair is replaced, repeat failure is highly possible. Inspect both gears, if either is worn, both must be replaced. Be sure to match replacement unit with original gear and shaft bottom.
The MAF sensor informs the engine control computer of the load on the engine by measuring airflow in grams per second of air over a sensing element or in the case of the VANE AIRFLOW sensor, the position of the door is measured as it is moved by the air entering the unit. This information is used by the ECM to calculate fuel delivery.
A malfunctioning MAF/VANE AIRFLOW sensor can cause any one or more of the following symptoms: hesitation, stalling, poor fuel economy or poor engine performance.
Visually inspect the sensor element in the MAF for damage or for a burnt smell. In the VANE AIRFLOW sensor, inspect the door for binding or for a burnt smell unit. Start the engine and tap lightly on the unit. If tapping causes an engine malfunction or intermittent operation the unit is faulty and must be replaced.
First check for and note any MAF/VANE AIRFLOW related trouble codes stored in the engine control computer. Inspect the wiring harness and connectors for damage. All MAF/VANE AIRFLOW relays MUST be checked for resistance (20 OHMS resistance or greater). Anything relay under this resistance must be replaced. Failure to do this will damage the replacement unit. Moisture entering the unit through split air ducts, or gas/oil fumes from the engine can also cause premature failure. Repair or replace as necessary. Correct any pre-existing conditions that caused stored trouble codes.
The most common causes are: worn vane assembly, cracked housing, or cracked printed circuit board. These conditions require unit replacement.
The most common causes are: cracked circuit boards, burned sensing filaments, poor solder joints, defective conformalcoat, or loose printed circuit board components.
Overvoltage sources from relays, shorted wiring, cracked printed circuit boards, moisture entering the unit through split air ducts, electrical connections and wiring, air intake obstructions or gas/oil fumes from the engine can cause failure. Check air filter and air ways for dirt or debris. Check for loose or faulty connectors, broken or faulty wiring. Be sure to check these to prevent damage to the replacement unit.