1. This page references our TIPM Plug-In Relay System or TIPM Plug-In Relay System (Lite) products with a focus on confirming the proper operation of either part.
  2. Both systems contain a PUMP ON green LED that is integrated into the design, per the red arrows shown below.  This LED will be lit when power is flowing to your fuel pump, which is the primary purpose of our parts.   
  3. The first thing to check on either part are the fuses to ensure they're not blown, since this will cause the PUMP ON green LED to not be lit and it will prevent power from flowing to your fuel pump.  Fuses should be checked visually and with an ohm meter.
  4. Then find a friend who can help you attempt to start your vehicle while you watch the PUMP ON green LED.  With the Lite version of the TIPM Plug-In Relay System, you will need to connect the included temporary ground wire per the part instructions in order the make the LEDs light up.
  5. Attempt to start the vehicle.

If the vehicle will not start, but the PUMP ON green LED is lit, our part is working properly and delivering power to your fuel pump as designed.  The most common issues we see in this situation are:

  • Cam or crank shaft sensors
  • Fuel pump has failed. Electrically test your fuel pump using a TIPM bypass cable or TIPM Plug-In Relay System when the vehicle is off to ensure the pump is working properly.  Our TIPM Plug-In Relay System (Lite) is not capable of testing your fuel pump.
  • Electrical connectors under the TIPM are corroded or not making good connections
  • Lack of fuel or fuel level gauge not working properly
  • You already have an external fuel pump relay installed where harness wires were cut under your TIPM.  This is considered an alternate method of bypassing a faulty fuel pump relay, mostly on 2011-2013 Durangos and Grand Cherokee vehicles.  Many people who purchased used vehicles are unaware if an external relay is installed, but this page will help you check if one is present.

If the vehicle will not start but the PUMP ON green LED is not lit during engine cranking, the most common causes are:

  • Ground wire not connected on either of our parts in order to properly make the LEDs light up. Our TIPM Plug-In Relay System must have a black ground wire connected all the time to function properly, but our TIPM Plug-In Relay System (Lite) only needs a temporary ground wire to make the LEDs illuminate.
  • Blown or missing fuses in our parts
  • K4 run/start relay that plugs into your TIPM has failed (try swapping it for another similar relay in the fuse box to confirm)
  • Our part has failed in some way

If the PUMP ON green LED is illuminated when the vehicle is off:

  • For the TIPM Plug-In Relay System, move the switch to the disable position.  If the PUMP ON green LED remains lit, it's possible that our part has been damaged in some way  

NOTE:  If you don't have our parts, you can always use a multimeter or test light with one end placed on top of the fuel pump fuse (M25 or F70) and the other end to chassis ground or battery negative terminal to detect voltage.   If using a multimeter or test light, you are trying to detect the presence of 12 VDC across the fuel pump fuse, which should only appear during engine cranking or while running.  A lack of or inconsistent 12 VDC often indicates a faulty fuel pump relay.

TIPM Plug-In Relay System (Lite) 

To allow the three diagnostic LEDs to illuminate, connect the temporary alligator clip ground wire as shown below.  Ensure the alligator clip is connected to the metal ring labeled "TP1" or "GND" and not to the plastic base below the metal ring.  Remove the alligator clip wire when testing is complete.

Connect ground wire to enable LEDs              

TIPM Plug-In Relay System

To allow the five diagnostic LEDs to illuminate AND to ensure the proper operation of the part, the included black ground wire must be permanently connected.  


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