I have BMW 535d 2005 automat, if i speed fast and the automat gear shifts from 4th to5th or if I'm driving on the 6th and it's kicking down to the 5th, I get a transnission fault and I have to swich off the car and turn it on again to get back to normal but in the therd time, the foult stays . If the gear shifts from 4t to 5th without accelerating fast, no fault will happen. The mechanic scanned the fault code and found the following.. 4F8A Not present EGS: Ratio monitoring, gearshift 4-5/.
I have the same problem. Any solution?
I have the exact same issue, have you fixed it?
Gear ratios are monitored from the input and out shaft speed sensors. Takes a scanner to watch the speed signals. These sensors are magnetized. If to much metal collects on them, this could mess with the signal. Could be a bad wire or plug to the sensor. Reading the code is just the first step. Next comes diagnostics. Making sure everything on the outside of the transmission is doing what is supposed to do, then going inside it.
Checks
Causes
1-2 Shift Solenoid Valve
?€¢
Inoperative
?€¢
Debris
?€¢
Pinched wires
3-4 Shift Valve Bore Plug
Misassembled
4th Band
Burned, slipping, missing
4th Servo Cover
Cracked
4th Servo Pin
Broken, seized
4th Servo Piston
Damaged
4th Servo Seals
Rolled, cut or damaged
4T65-E
Slipping or No Fourth Gear
Slipping or No Fourth Gear Checks
Cause
DEFINITION: A large engine RPM increase is noted in fourth gear, Drive range, with little or no vehicle forward speed increase. First, second, and third gear operation are normal. Shifts into fourth gear are soft or do not occur. Fourth gear ratio is 0.705:1.
Automatic Transmission Fluid Level
Low fluid level
Transmission Main Line Pressure
Low transmission main line pressure
Oil Filter Assembly
• The oil filter assembly (100) is missing, plugged, or damaged.
• The oil filter seal assembly (101) is missing or is damaged.
Control Valve Body Assembly
• The 3-4 shift valve (362) or the 4-3 manual downshift valve (360) is stuck or binding.
• Debris is found in the passages of the control valve body (301) or of the control valve body spacer plate and gasket assembly (396)
Case Cover Assembly
Distortion or damage occurs at the manual valve (404) or at the case cover (401), causing PRN oil leak.
Driven Sprocket Support Assembly
A plugged third clutch oil passage in the driven sprocket support assembly (609)
Fourth Clutch Assembly
• The clutch plates (500-502) are worn, damaged, or misassembled.
• A missing or not seated fourth clutch spring retaining ring (601)
• A damaged spring assembly (602) or piston (603)
• Worn or damaged fourth clutch piston seals (604, 605)
Third Clutch Sprag Assembly
• The sprag (720) was misassembled or backwards on the inner race (661).
• A damaged third clutch sprag assembly (653, 661, 719-721)
Trouble Code Conditions:
Vehicle driven to a speed of 4-37 mph at more than 500 rpm, gear selector in 4th Gear in Drive, and the PCM detected too much difference in the engine speed and output shaft speed.
Possible Causes:
Trouble Code Conditions:
Vehicle driven any forward Gear, and the TCM detected the ratio of the Input speed to the Output Speed did not match the current Gear Ratio (this test can take up to 5 minutes).
Possible Causes:
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