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Q1 - I understand you get no sound when you turn the key to start. Do the lights stay illuminated during these attempts?
Q2 - Have you recorded the diagnostic trouble codes stored in your PCM? Autozone and others will collect these for free.
I do not have an explanation in regards to why you can start after pulling and replacing the start relay but weird electrical issues are often tied to poor ground connections.
BTW - I had a similar issue years ago and my issue was a corroded connection between the battery and CJB (on the bottom of the CJB) your issue appears to be somewhat different.
The PCM has a total of five connector pins in connector C175B (seventy pin locations available) that tie to ground G103 (see below). For future reference the pin numbers are 66, 67, 68, 69 and 70 are grounded. In the connector pins 67, 68, 69 and 70 sit off to the side by themselves in one vertical column (66 sits at the bottom of the long column of pins). C175B is the center, large, connector on the PCM.
Using the proper precautions (disconnect battery), my may want to inspect those pins for corrosion or other issues. Use care so that nothing gets damaged or grounded while the pins are exposed.
In regards to grounds related to the PCM (some others are listed for clarity) -
I doubt these are related to your no start issue
There are four grounds located within 6-inches of the PCM on the firewall and in general these are not problematic, takes two minutes to check them all. The one on the firewall closest to the passenger side fender is designated G103 and is the most important one.
So, near the PCM on the firewall are four grounds
1. G103 (near fender) is for PCM and other very important sensors/devices (to name some, MAF, cam position, MAF temperature, etc)
2. G102 (between G103 and PCM) for PCM body ground and a data link connector
3. G101 (partially behind PCM on the firewall) bonds (connects) Negative side of battery to firewall
4. Engine ground (2" to the right of PCM)
I hope this helps. Please keep us informed of your progress.
A1 - All the lights in the instrument panel remain on...and it just happened again - relay was clicking when I went to crank.
A2 - I have an edge programmer with custom tunes from PHP, so I have continuous access to the codes. This "no start" condition hasn't thrown any codes.
I'll check for corrosion on those PCM pins this weekend. I'm also still chasing grounds, thanks for the additional info! Below is status:
Additionally, I replaced the transmission range sensor yesterday. What I thought was corrosion, after being able to look better...was actually some white dielectric grease on the tips.
Last edited by callaway29; 07-23-2022 at 04:02 PM.
Closing the loop on this one... I threw a hail mary and replaced the starter and wiring harness. The problem appears to be resolved! Thank you all for the advice.
Last edited by callaway29; 08-04-2022 at 06:32 PM.
Callaway29,Many, many of the posts in this forum (and others) are open ended. Problem stated, solutions suggested but no closure. Thank you for posting feedback that allows future readers to understand and consider your experience with the issue.
Jimboy
Callaway29,Many, many of the posts in this forum (and others) are open ended. Problem stated, solutions suggested but no closure. Thank you for posting feedback that allows future readers to understand and consider your experience with the issue.
Jimboy
These boards are an incredible resource. I'm happy to do my part...
Originally Posted by BareBonesXL
Which wiring harness? If it wasn't the one attached to the starter relay it's hard to see how it could be the solution.
Two posts ago it was the range selector. Just saying. Good luck.
The wiring harness for the starter (from battery to starter). I'm not sure what you mean by "two posts ago it was the range selector". Perhaps two posts ago I said I replaced the range selector, but I never said it fixed the problem...? It's been five days without issue and it was happening every other day, so I'm cautiously optimistic it's resolved...but fingers crossed. Thanks again.
I just don't see how removing and replacing the starter relay (your first post, copied below) meshes with replacing the starter and starter wiring harness. There's no logical reason for those things to be connected except for a wire or two.
Yes, I was referring to the range selector. That part didn't fit your initial symptoms either. It's not a criticism it's just a reality.
The things you did don't follow from the original symptom. If it does stay fixed the best explanation is that you bumped something while you were replacing those unrelated parts. But I wouldn't be surprised if the problem comes back. No offense intended. Good luck.
Originally Posted by callaway29
I've learned if I pull the starter relay out, and plug it back in...truck will start. I've been able to reproduce this "fix" a few times.
I just don't see how removing and replacing the starter relay (your first post, copied below) meshes with replacing the starter and starter wiring harness. There's no logical reason for those things to be connected except for a wire or two.
Yes, I was referring to the range selector. That part didn't fit your initial symptoms either. It's not a criticism it's just a reality.
The things you did don't follow from the original symptom. If it does stay fixed the best explanation is that you bumped something while you were replacing those unrelated parts. But I wouldn't be surprised if the problem comes back. No offense intended. Good luck.
If latest step did resolve it, it could also have simply been a dirty/bad/loose connection of original cable connections.
This guy has a similar problem. I'll bet callaway29's problem came back. The solution just didn't fit the problem at all. Overall it seems more like a computer problem. Some sort of transistor in a control module that isn't changing state when it's supposed to. Glad that my 2003 is still pretty primitive.
07-19-2022, 03:57 PM
