Engine control unit on Honda especially p06s p28 p13 p72s like almost all obd1 ECU
Solid CEL: What is It?
A solid cell Depending on how it shows up, you either have a solid cell and a fuel prime or you have a faulty memory, incompatible internal programs, or a power problem.
Why Solid CEL occurs
Solid cell and no fuel priming as you can see in this issue, the capacitors completely leaked and damaged the PCB; you can see here that all of the green coating on the PCB has disappeared due to the capacitor leaking. If you don’t have a fuel prime and still have a solid cell, it would be the memory. If you don’t have a fuel prime and still have the solid cell, it would be a power issue.
What are you able to do?
Replace the capacitors, which will obviously fix the issue in some cases. However, if that doesn’t work, you’ll need to replace this IC, which is called IC17. Its function is power regulation, so it receives five volts from the regulator, confirms, and verifies the voltage, and then outputs the voltage to the entire logic board because this part is the logic board and this part is the power board. You have all the transistors for the injectors, one for the solenoid, and one for the v tec. You have all the transistors for the injectors since this portion is the logic board and this part is the power board. This one is for automatic transmission, so you also have the transistor for the solenoid: this one is for the v tec.
Conclusion
You will have a solid cell and no fuel prime if this IC is malfunctioning, and a fuel prime but a solid cell if the memory is corrupted.