wow, you changed the ignition control module, crank sensor, and coil packs and no spark?
Take to an auto electric shop where they can test the wiring to see if there are any breaks between the sensors or parts you already invested in.
Can your scanner communicate with the PCM?
Powertrain Control Module (PCM)
The OBD 2 Engine Management System (EMS) computer can be a single computer comprised of several solid-state components or a multi-microcomputer device. This computer controls the functions of the EMS and performs OBD 2 diagnostic routines. These two distinct portions of the OBD 2 EMS computer function, in conjunction, with each other. The computer architecture and software design allows the OBD 2 EMS computer to adapt its operating strategies to a variety of conditions to optimize the EMS. Federal guidelines require the EMS OBD 2 computer to continuously monitor the operating conditions of the EMS. It must also record and report any system or component failure that may cause tailpipe emissions to exceed typically 1-½ times the federal test procedure.
The OBD 2 EMS computer is specifically designed to perform powertrain system management and monitoring. Regardless of the manufacturers design and implementation of operating strategies, all computers are designed and built following the same basic considerations.
All computers contain one or more microprocessor. Microprocessors are constructed of a complex arrangement of digital circuits. One microprocessor may contain upwards of 250,000 logic circuits. These are housed in a silicon-based integrated circuit (IC) no bigger than an area of approximately ¼ inch square. The microprocessor cannot perform calculations and decisions without instructions that are programmed into the computer’s memories.
IC Micro Processor
One single microprocessor, called the Central Processing Unit (CPU), is dedicated to maintaining control over the entire computer. The CPU performs all of the calculations and logical decisions. Operating instructions for the CPU are preprogrammed into other memory locations and are ‘read-only’ programs. These programs are permanent and generally cannot be altered by service personnel in the field.
A program, in general, is a set of instructions arranged in a specific order to accomplish a specific task. Each instruction in the program is assigned to a specific location, or address within the computer’s memory. Only the address of where the instruction is stored is retained in the CPU. When the CPU requires information to perform a calculation, it looks for the address of the required data and then copies the data from the memory location. This copy is retrieved and temporarily retained by the CPU for processing. Retrieving programs in this manner ensures that the information programmed in memory is retained and does not change.
The following symptoms can be caused by an open, short to ground, short to power or excessive resistance in the power and ground circuits, data line communication malfunctions and /or component failure.
- No Crank
- No Start condition
- No communication with scan tools
- No communications with other modules
- MIL lamp illumination
- Intermittent component functions
- Poor fuel economy
- High emissions
- Drivability concerns (stalling, bucking, stumble etc.)
- Charging system malfunctions