Pcm Code EO55, TPS Out Of Adjustment: Action:

At next key on, PCM will log Code EO55 as current. No diagnostic light or service message will appear.

The TPS is self-adjusting. With key off, the PCM executes a TPS learning routine. After turning key off, the PCM will retract ISC until the ISC throttle switch opens and throttle linkage is resting on the minimum air screw. At that time, PCM stores TPS value and calculates a correction.

If the same correction factor occurs on 2 consecutive key off cycles, TPS is corrected to zero degrees using correction factor learned. If value needs correction by more than -2.9 degrees or +3.0 degrees, Code EO55 will be stored in memory at next key on cycle. Parameter ED01 displays uncorrected TPS values.

1. This step checks TPS adjustment. PCM parameter ED01 displays uncorrected TPS so that it can be used to check TPS adjustment.
2. TPS adjustment is okay.
3. If TPS adjustment is okay, ISC and throttle switch operation need to be thoroughly checked. The throttle linkage needs to be checked proper operation. Throttle and cruise cables, throttle valves not binding, proper throttle return spring operation, and throttle shaft and blades free to move.