Toot Your Own Horn!
As Denny Gipe from Dennis Gipe Transmissions in Chambersburg, Pa., mentioned in this month’s Shift Pointers article, ATSG has experienced the P0123 code in late-model Jeeps using the 2.5- or 4.0-liter engines and the AW4 transmission. P0123 indicates TPS voltage high, and in these vehicles it produces a complaint of no upshift. One cause for this condition is the horn’s 12-volt clock spring inside the steering wheel short-circuiting with the cruise-control’s switch-sense wire (Figure 1).
