w140 s320 1996 model NO fifth gear

hi friends, I have s320 1996 model with 722.5 gear it was working fine till I parked it for 1.5 months in dusty area, when I came back I found battery drained so I recharged it, after turning on the car there was black smoke and irregular rpm, I thought it is the MAF, and the car stopped engaging the fifth gear, I changed my MAF with a new Bosch one, and changed the fuel pump , fuel filter and gear oil and filter with original ones, the irregular rpm and smoking resolved but still does not engage fifth, I checked the D switch and I found the shifter is broken, so I changed the switch mechanism into a direct on mechanism (so the shift is supposed to be always in D mode) still not engaging fifth, manual check in repair centre showed that the fifth connection on the tranny itself has no electric current on speed and rpm which should give it the electric order to engage fifth, i.e. there is a cut anywhere in the electric connections which control fifth engagement, the computer test gave the following:
- camshaft timing solenoid y49 not functioning
- cable to starter lockout relay module function defective
- O2 sensor defect
- fuel pump relay defect

now I do not know what to do else, are these error codes related to my fifth gear problem, where can I find an illustration for other switches and relays and pressure valves and lines controlling fifth upshift to check them myself


any help will be greatly appreciated , thank you friends