Trouble Diagnosis: Fail-Safe: Notes

The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is a malfunction in a main electronic control input/output signal circuit.

In fail-safe mode, even if the select lever is "D" or "M" mode, the transmission is fixed in 2nd or 4th (depending on the breakdown position), so the customer should feel "slipping" or "poor acceleration". When fail-safe mode is triggered, when the ignition switch is switched "ON", the A/T CHECK indicator lamp flashes for about 8 seconds. (Refer to "TCM SELF-DIAGNOSTIC PROCEDURE (NO TOOLS) ").

Even when the electronic circuits are normal, under special conditions (for example, when slamming on the brake with the wheels spinning drastically and stopping the tire rotation), the transmission can go into fail-safe mode. If this happens, switch "OFF" the ignition switch for 10 seconds, then switch it "ON" again to return to the normal shift pattern. Also, the A/T CHECK indicator lamp flashes for about 8 seconds once, then is cleared. Therefore, the customer's vehicle has returned to normal, so handle according to the "DIAGNOSTIC WORKSHEET " (Refer to "DIAGNOSTIC WORKSHEET ").