Code 14 12 indicates the ECU has detected a voltage signal in the low error zone.
OLS ground wire 135B is common to the TPS and the RMR devices. A power wire short-to-ground for any of these devices will cause ?sensor failed low? codes (21 12 and 64 12). An OLS signal open or short-to-ground results in a Code 14 12 only.
Possible causes:
1) Faulty wiring to the OLS
2) A faulty OLS
3) A faulty ECU
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Allison WTEC II Fault Code: 13 PID: SPN: 12 FMI: ECU input voltage, low
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