My 94 Corolla's overdrive blinking code is 63 then 64. What does this correspond to?

Here's the link and I'm sure you will get the solution of the problem

https://www.reliable-store.com

no idea on autos as not many here in europe ,but on a vehicle this old look for a vacumn pipe from inlet manifold to the gearbox.

if the check engine light is on then you will have to have the code pulled so you know what tests have to be done to find the cause of the problem.

O/D light flashing indicates a fault in the transmission. Manuall diagnose by bridging terminals Te1 and e1 on the diagnostic socket. refer to repair manual on the code got.

Bad sensor. Cannot say exaclty which one, but I would assume the throttle position sensor. Could possibly be the switch on the shifter needs replacing, or the overdirve relay needs to be replaced.

Below is a method you can "self diagnose"


To get codes out of the Transmission Control Module (TCM). The lamp in the Overdrive OFF switch is used to signal the various flash codes. To view flash codes, proceed as follows:

1. Turn ignition key ON-OFF-ON-OFF-ON finally leaving the key in the ON position. Leave the Overdrive OFF Switch in the normal overdrive (ON) position.
2. Immediately begin counting the number of flashes displayed by the Overdrive OFF Switch indicator lamp.
3. Flash codes will correspond to Powertrain Control Module codes in duration and spacing.
4. A code 55 identifies the end of flash code transmission.

And the possible codes are:

• 11 No Engine Speed Sensor Signal
• 12 No Output Shaft Sensor Signal
• 13 No Vehicle Speed Sensor Signal
• 14 Governor Pressure Sensor Signal
• 15 Throttle Position Signal
• 16 Transmission Temperature Sensor
• 17 Overdrive Off Switch Circuit
• 18 System Voltage Out of Limits
• 19 Standby Voltage Out of Limits
• 21 Governor Pressure Solenoid Circuit
• 22 3-4 Solenoid Circuit
• 23 Torque Converter Clutch Circuit
• 24 Overdrive Off Lamp Circuit
• 25 EEPROM Checksum Error
• 26 Governor Pressure Sensor Offset Drift
• 55 End of Message

If you still get no codes, then we have to explore a mechanical problem inside the transmission. Possibly the overdrive solenoid not venting or a lower valve body malfunction.

best of luck and let us know?

Replace the switch you must have broken it

Remove the master cylinder & take out the
piston & clean inside

Replace all rubber flex hoses & any calipers & wheel
cylinders over 8 years old

Flush System

Had same problem on my 94 eldorado touring and it turned out I had bad ign coil. This sets a 41 code. Check codes for no cam ref signal. Sounds stupid but if one coil stops firing on only one cyl it sets that code. There are 4 coils and they run 2 of one end of ign module and two of other end.

Take a compression test on # 4. It may be a little oil burning w coolant getting by the head gasket. POSSIBLE faulty injector or not firing on time. Ck for any oil in the anti freeze or anti freeze in the oil.

Have the vehicle scanned.The overdrive light is like the check engine light for the transmission. There are transmission codes in the ecm if the overdrive light is blinking.