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Direct Injection FIX
Posted to Technical Tips Forum on 2/24/2015 7 Replies

2010 Buick La Crosse CXS 3.6 L with direct fuel injection system.

Vehicle came into shop with complaint of hard start, runs poorly, runs rich and may pop back into intake on acceleration. Vehicle will go into reduced power mode. Repair history in the past 6 months is New -- High pressure fuel pump, 2 fuel lines, pressure sensor, bank1 sensor 2 oxygen sensor, #1 injector.

Codes retrieved were P2178 fuel trim rich at cruise or acceleration bank 1 P2180 fuel trim rich at cruise or acceleration bank 2 P0089 fuel pressure regulator performance P0300 P0301 P0302 P0303 P0304 P0305 P0306 P2189 fuel trim lean at idle bank 2

Vehicle was very hard to start. It would crank up run a few seconds and die like very low of gasoline. Cleared codes and most codes would return. Also P0088 fuel pressure high and P0089 fuel pressure regulator performance along with miss-fire codes. This Fuel rail pressure sensor reading has been jumping around a lot when running, for example at idle it might go from 1 Mpa to 6 Mpa. Each Mpa is equal to 145 PSI. With key on engine off the Mpa measurement would stay steady for example 4 Mpa.The Tech 2 will not communicate with this model. Call ACDelco and they confirmed that it will not. Our Autel will though. The Autel has the ability to control the pressure regulator which is part of the high pressure fuel pump. As we control the pressure up we should see a corresponding increase in Mpa in the fuel rail pressure sensor. The pressure sensor did increase and the high pressure pump (driven by the camshaft) would start singing going up to 17 Mpa. It sounds like it is stressed, as it ought to be. We searched iATN, Google, talked to dealership and came up with nothing. Tried wiggle wires to the system injectors, pump and sensor with no change. The injectors and pressure sensor are under the intake. Pondered new injectors, ECM, wiring, another pressure sensor?

Removed the intake and checked connection to pressure sensor, looked fine. Turn key on (will set codes because of removed intake, throttle, tps etc) watched readings on fuel rail pressure sensor and noticed they did change when wiggling connector. Tugged on the 3 wires a little and Boop the white wire came loose. Replaced the connector with part # ACD- [2010 Buick LaCrosse CXS, ECM/Inputs/Outputs Photo] PT2798 (did not show under application we only found it by the pigtail chart matching up). The pressure sensor part # is 12621292.

Problem is FIXED

I believe this problem will occur on other direct fuel injection vehicles because of the location of the sensor and connector near the top of the heat of the engine.

Daniel from Tennessee

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car Vehicle Data

2010 Buick LaCrosse CXS 3.6L

Engine3.6 L
Trans6-speed Automatic (Electronic)