Diagnostic Aids

With ignition on and engine stopped, manifold pressure is equal to atmospheric pressure and the signal will be high. MAP sensor is also used for altitude compensation. This information is used by ECM as an indication of vehicle altitude and referred to as barometric pressure. A Code 34 will result if circuits No. 416 or 432 are open or shorted to ground. An internally shorted TPS will cause a Code 34. If Code 34 is intermittent, see INTERMITTENTS in TESTS W/O CODES article.

Fig 1: Code 34, Circuit Wiring Diagram

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code 34, Flow Chart

Courtesy of GENERAL MOTORS CORP.