Fail-Safe Remarks
FAIL-SAFEThe A/T control unit has an electronic Fail-Safe (limp home mode). This allows the vehicle to be driven even if a major electrical input/output device circuit is damaged.
In this condition, the vehicle runs in third gear in positions 1, 2 or D and will not upshift. Customer may say "Sluggish, poor acceleration".
When Fail-Safe operation occurs the next time the key is turned to the ON position, the A/T check lamp will blink for about 8 seconds.
Fail-safe may occur without electrical circuit damage if the vehicle is driven under extreme conditions (such as excessive wheel spin followed by sudden braking). To recover normal shift pattern, turn ignition key OFF for 3 seconds, then ON.
The blinking of the A/T check lamp for about 8 seconds will appear only once and be cleared. The customer may resume normal driving conditions by chance.
The SELF-DIAGNOSIS results will be as follows:
The first SELF-DIAGNOSIS will indicate the damage of the vehicle speed sensor or the revolution sensor.
During the next SELF-DIAGNOSIS performed after checking the sensor, no damages will be indicated.
ATF COOLER SERVICE
If excessive foreign material is found in oil pan or clogging strainer, service ATF cooler as follows:
- Fin type
Replace radiator lower tank (which includes ATF cooler) with new one, then flush cooler line using cleaning solvent and compressed air.