The pressure that is measured with the pressure gauge for each step and the pressure that is displayed on the electronic service tool for each step are within 1379 kPa (200 psi). Consult your owner’s manual or contact your local Cat Dealer for more information. The ECM uses signal from the boost sensor and atmospheric sensor to determine the fuel that will be delivered , the ECM also calibrates its other pressure sensors from that sensor, if there is a high voltage fault or open circuit to that sensor the ECM sets a default of 100kpa CAT 3126 Engine Electrical Drawings pg 4.jpg (155.1 kB, 704x1024 - viewed 7206 times.) All proceeding readings taken @ idle. CAT 3126 Engine Electrical Drawings pg 3.jpg (180.29 kB, 1280x880 - viewed 8491 times.) Re: Location of the oil pressure sender/Sensor 3126b Cat « Reply #3 on: June 27, 2017, 01:48:47 PM » Tom, location for oil sensors on Cat 3126 B engine ( if Equiped depending on engine S/N. It is not necessary to remove inlet manifold temperature sensor (1) or inlet manifold pressure sensor (2) . CAT 3126 Engine Electrical Drawings pg 2.jpg (198.67 kB, 1280x880 - viewed 18911 times.) Results: Yes - The injection actuation pressure sensor is operating properly. • Low pressure sensors are primarily used on engine related applications such as air systems, exhaust after treatment systems, fuel systems, engine oil systems, etc. A restricted fuel filter will cause lower fuel pressure at tap (10) than at tap (8). Install the adapter, seal and 1U5470 Engine Pressure Group to fuel pressure tap (8). Note: Cat ET will report the status for atmospheric pressure as the ambient barometric pressure. I don't have any mechanical boost gauge to compare to, so i can't verify the accuracy of the Scan Gauge. ICP gauge @ 0 , Oil pressure @ 27.5 , HPR @ 26 , LOD @ 22 , PSI Barometric pressure @ 14.2 , VLT @ 13.9 - 14.1 Volts during data sample. 2003 3126e showing code 164 / FM 3 . Class A RV Frieightliner chassis 3126e CAT turbo 330 engine ; How to trouble shoot code(s) & repair them. The readings for the turbocharger inlet pressure sensor will be approximately the same value that is reported by the atmospheric pressure sensor. The approximate same value readings will occur while the engine is not running. It is responsible for measuring the atmospheric pressure of the environment that the vehicle is driving in. « Last Edit: September 21, … SMCS Code: 1925-081. System Operation Description: Use … ... location of the injection actuation pressure control valve. CAT 3126 Engine Electrical Drawings pg 1.jpg (163.98 kB, 1280x880 - viewed 2908 times.) Proceed to Test Step 12. Connect the 1U-5470 Engine Pressure Group to the inlet manifold at the pressure test location.Refer to Special Instruction, SEHS8907, “Using the 1U-5470 Engine Pressure Group” for more information on using the tool. The barometric sensor, also commonly known as the barometric air pressure sensor (BAP), is a type of engine management sensor commonly found on many vehicles. To my surprise under heavy load my 98 Cat 300HP 3126 is hitting 50 psi of boost! NOTE: Make sure the fuel filter is clean before checking fuel pressure. (1) Engine coolant temperature sensor (2) Fuel pressure sensor (if equipped) (3) J500/P500 Injection actuation pressure control valve connector (4) Injection actuation pressure sensor (5) Boost pressure sensor (6) Air inlet temperature sensor (7) J300/P300 Injector valve cover entry connector (8) Atmospheric pressure sensor ECM uses the reading from the injection actuation. • Cat pressure sensors are application specific sensors. RPM @ 748. OK, so I installed one of the new Scan Gauge D units. disconnected, the voltage test lamp will remain on. That seems a bit much. Operate the engine. the injection actuation pressure sensor is not. It shows BST boost PSI as supplied by the ECM. To check in the main gallery for pressure, remove the plug from fuel pressure tap (10).