@iamretired it does go through the transmission range sensor. The Transmission Range (TR) sensor , which is located at the manual lever on the transmission is an information sensor for the powertrain control module (PCM). Among its functions are those normally handled by a conventional Park/Neutral switch: it prevents the engine from starting in any gear other than Park or Neutral. and closes the circuit for the back-up lights when the shift lever is moved to Reverse. The TR sensor also contains the sensing circuit for Neutral in 4X4 Low range on 4WD models.It should be located on the shift lever side on the transmission.
Looks like if you place a jumper between the LtBlu/Pnk wire and the Blk/Pnk wire it'll bypass the reverse sensor and should turn your backup lights on. If so, you know its your TP Sensor that has failed.
9 opmerkingen
Thanks oldturkey03 - All functions seem to be working except for the backup lights, so for now I will assume that the TR sensor is working OK. I will now attempt to trace the wiring to the backup lights looking for a short or broken wire. Can you tell me which mini fuse and/or relay is associated to the backup lights?
door Tom Richards
Dumb question but did you check the bulbs and their connection? My Suburban has lose connections and does this with daytime lights. If I recall on my 2003 Expedition (Built on a F-150) it should be on the left stick, but It broke down 3 or 4 years ago so it has been a while.
door MaxAwesomeness GB (Max)
Yes I did, and both bulbs tested good. I tested the connections at both bulbs, and both showed a closed circuit, which leads me to suspect a short somewhere. However, I am going to repeat the test, but this time with both bulbs out at the same time. I think that maybe leaving the right side bulb in while testing the circuit at the left side was giving me a false reading, and visa versa. Maybe do this tomorrow - pouring rain right now! And it is not a dumb question.
door Tom Richards
@iamretired I would not be so quick as to dismiss the TR sensor. I think that beast is merely using a cam system from the shifter linkage to close a switch. I believe there are some adjustments you could make. check original answer for wiring update
door oldturkey03
Thanks old turkey03 - Me thinks the next thing I will do is to enlist my neighbours help and check out the switch adjustments, It sounds like a two person job, one to work, and one to watch.
door Tom Richards
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