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DTC 522711 ETC TPS 1 Range
Conditions for Setting the DTC
Electronic Throttle Control
Check Condition-Ignition ON
Fault Condition-TPS 1 voltage below 0.2 TPS 2 voltage greater than 4.95
MIL-On during active fault
Circuit Description
The electronic throttle body has two throttle position sensors TPS1 and TPS2. The voltage from these
sensors is used to determine the percentage throttle opening. The TPS sensors have a nominal output
range of 0.2 to 4.95 volts. From the throttle body itself TPS1 ranges from 0.2 to 4.95 volts as the throttle is
opened, TPS2 ranges from 4.95 to 0.2 volts for this same closed to open travel. The ECM rectifies TPS2
signal so both signals on the diagnostic monitor read from 0.2 to 4.95 as the throttle is opened. The travel
of the throttle plate from the fully closed to the fully open mechanical stops may not use this entire range of
voltages. The ECM learns the actual range of voltages used and adjusts the THROTTLE POSITION read-
ing to range from 0 to 100% over this used range of voltages. The system looks at both TPS signals and if
the readings are outside of the upper and lower limits or do not agree with each within limits a code will be
set. The following failure combinations and resulting outcomes are possible:
a) TPS1 fails open or shorted, - MIL illuminated, ECM uses TPS2, normal engine operation
b) TPS2 fails open or shorted, - MIL illuminated, ECM uses TPS1, normal engine operation
c) TPS1 & 2 fail open or shorted, - MIL illuminated, ECM stops controlling throttle, throttle goes to limp
home position and is non-responsive, engine will high idle or allow truck to move slowly.
d) TPS1 & 2 do not match, - MIL illuminated, ECM will use the higher of the two TPS readings resulting in
normal or less than normal engine power.
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