1. Cause of failure  

(1) The diesel engine operates with reduced load under conditions such as high altitude and clogged air 

filter.  

(2) The throttle switch is not working properly. 

 (3) The ECM power supply, ground wire or connector is faulty. (4) The fuel system is faulty. (5) The 

injection drive pressure is too low.

 2023 CAT ET 2023A 2023C & 2019C Full Service Download and Installation Service

2. Troubleshooting 

 (1) Use ET to check recorded diesel engine load reduction and/or current existing diesel engine load 

reduction conditions. If the diesel engine load reduction operation currently exists, then the ET will 

display the load reduction operation status signal. At high altitudes, with dirty air filters and other 

conditions, the diesel engine will run at reduced load. 

 (2) Monitor the throttle switch on the ET and check whether the throttle switch is working properly. 

Please refer to Section 11 and 15 of this chapter. 

 (3) Ensure that ECM connectors J1/P1 and J2/P2, injector connector J300/P300, camshaft position 

sensor connectors J401/P401 and J402/P402 are installed correctly.

  (4) Use electronic maintenance tools to check the fault code 0168-02 (intermittent battery power to 

the 

ECM), check the electrical connector and grounding wire of the ECM, if a fault is suspected, use wires 

to bypass it, please refer to Chapter 11 Contents of Section 5.

  (5) Monitor the fuel configuration value, rated fuel limit value and FRC fuel limit value through ET.

  ①If the fuel configuration value is equal to the rated fuel limit value and less than the FRC fuel limit 

value, it is said that the electronic component is working normally. 

 ② If the fuel configuration value is not equal to the rated fuel limit value and/or is greater than the 

FRC 

fuel limit value, then when the diesel engine is turned off and the ignition key switch is turned to the 

ON position, the turbocharger outlet pressure on the electronic maintenance tool screen should be 

OkPa, 

 (6) Check the fuel system, please refer to Section 6.4. 

 (7) Check the injection drive pressure.