Diagnosis And Testing - Light Load Switch
WARNING: This page is about a different car, the 2011 RAM Pickup and 2011 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
In order to obtain conclusive testing, the Tire Pressure Monitor (TPM) system and the Controller Area Network (CAN) data bus circuit must be checked. Any diagnosis of the TPM system should begin with, the use of a scan tool and the appropriate diagnostic service information .
Refer to the appropriate wiring information for complete wiring diagrams.
- Remove the light load switch. Refer to SWITCH , Removal .
- Disconnect the wire harness connector from the back of the light load switch. Check for continuity between the light load switch harness connector cavity terminal 4 and a good ground. Resistance should be less than 5 ohms. If OK, go to the next step, if not OK repair the ground circuit of the light load switch.
- Test the continuity of the light load switch (component side) between pins three and four with the switch depressed (closed) and with the switch released (open). There should be continuity (less than 100 Ohms) with the switch depressed and no continuity (infinity) with the switch released. If OK, go to the next step. If not OK, replace the light load switch. Refer to SWITCH , Installation .
- Test the TPM switch signal circuit between the light load switch harness connector cavity 3 and the instrument cluster harness connector C3 cavity 5 for an open or short to ground. Repair the circuit as required, and install the light load switch. Refer to SWITCH , Installation .