BRACKET AS 2692860 - Caterpillar

3176 (7LG) Truck EnginesSUPPLEMENT: 07/00/91Truck Engine News, May 1991, Page 4, "Inlet Air Temperature Sensor Added And Fuel Pressure Sensor Removed From Engine Control System " on 3176...7LG Truck Engines. The Parts List chart at the end of the article is not complete. The complete Parts List follows. --------------- END SUPPLEMENT ---------------An inlet air temperature sensor and diagnostic code 38 " Inlet Air Temperature Sensor Fault" have been introduced on the 1991 3176 Truck Engine. The fuel pressure sensor, diagnostic code 37 "Fuel Pressure Sensor Fault", and diagnostic code 63 "Low Fuel Pressure Warning" have been eliminated. Current 3176 Truck Engine publications do not reference the inlet air temperature sensor system operation, ECAP screen information, diagnostic code explanation, troubleshooting procedure, and additional parts. This article is intended to be a source of this information, until the publications are updated.
This article also includes sections entitled "ECAP Information, " "Diagnostic Information," "Troubleshooting, " and "Parts List." These sections are intended to supplement the present 3176 Truck Engine publications until updated versions are available.An inlet air temperature sensor has been added to the 1991 3176 Truck Engine to control fuel injection timing during cold inlet air/warm inlet air operation. Diagnostic code 38 "Inlet Air Temperature Sensor Fault" has been added to identify an inlet air temperature sensor system fault. The coolant temperature sensor is also part of the inlet air temperature system strategy. The ECM corrects the inlet air temperature sensor signal for effects of external engine heat based on the engine coolant temperature. The inlet air temperature sensor became effective with engine serial number 7LG02259.
The 9X5370 Inlet Air Temperature Sensor is the same sensor that is used for coolant temperature. The sensor is mounted in the top of the inlet manifold, to the rear of the inlet port. The fuel pressure sensor wiring harness connector (J16) is connected to a 4P9612 extension wiring harness that connects to the inlet air temperature sensor (J21). The fuel pressure sensor has been removed from the 3176 Truck Engine. A new personality module has been released for each 3176 Engine Family to control the system strategy.ECAP (Electronic Control Analyzer Programmer) Information
1. The ECAP will be unable to monitor the Inlet Air Temperature Sensor temperature through the ECM until the June 1991 update SPM (Service Program Module), NEXG4522. (The Coolant Temperature Sensor reading can currently be viewed from an ECAP through the ECM, and is used as part of the Coolant Temperature Sensor Test in the 1991 3176 Engine Troubleshooting Guide, SENR5112.)2. The Fuel Pressure Sensor reading on the ECAP status screen will be set to 0 psi. Diagnostic Code 37 "Fuel Pressure Sensor Fault" and Diagnostic Code 63 " Low Fuel Pressure Warning" are disabled.3. Diagnostic code 38 is now enabled. Until the June 1991 ECAP SPM is available, the ECAP will indicate Diagnostic Code 38 as "unassigned". The ECAP user will also see the following message on the ECAP with the NEXG4507 VERSION 1.2 SPM until the new SPM is available:
This 3176 Truck