TIP- 1358252 - Caterpillar

Illustration 1 g03368122
Straight Travel Control pressure tap
Install a pressure gauge at the Straight Travel Control pressure tap. Use a long hose so the pressure gauge can be monitored from a safe location.
Start the machine. With 0A commanded to straight travel, the control pressure should be the same as the pilot system pressure. If pressure is not within specifications, refer to Testing and Adjusting, UENR4275, "Relief Valve (Pilot) - Test and Adjust" to adjust pilot system pressure.
Use Cat ET to override current for the straight travel valve to 2A.
Verify the measurement of 2A at the straight travel PHMV. If measurements are not within specifications, inspect the harness for shorts. PHMV solenoid resistance should be 5 0.3Ω. If resistance is not within specifications, replace PHMV and update calibration slope in the software using Cat ET.
When 2A is sent to the straight travel PHMV, straight travel control pressure should drop close to 0 psi. If the control pressure does not drop when 2A is applied to the solenoid, the PHMV solenoid has failed. Replace the PHMV solenoid, and update the calibration slope in the ECM software using Cat ET.