DTC P176D-12: IG2 Signal (Gear Shift Control Module "A") Circuit Short to Auxiliary Battery [09/2023 - ]: Description

WARNING: This page is about a different car, the 2024 Lexus TX 500h. However, it is still accessible from the selected car via links, so may be relevant.

The shift control ECU compares the IGP signal to the IG control status signal sent from smart key ECU assembly (certification ECU assembly) to detect a stuck on malfunction of the IGP signal.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate	DTC Output from	Priority	Note
P176D-12	IG2 Signal (Gear Shift Control Module "A") Circuit Short to Auxiliary Battery	When all of the following conditions are met: The ignition switch is turned off after a few seconds have elapsed since the ignition switch was turned to ON (READY). Although the control status signal from the certification ECU is off, the IGP status signal is on. (1 trip detection logic)	Certification ECU (smart key ECU assembly) Shift control ECU (transmission floor shift assembly) IGP NO. 1 RELAY Wire harness or connector	Does not come on	Multi-information Display Error Message Displayed	Hybrid Control	A	SAE: P176F