I had both CATs, 6 coils & plugs, alternator, and gaskets replaced a few days ago, (read $$$$), on my lovely 109k mile 2002 2.5L automatic (VIN ending in C85902) and everything was great - for a while. I stopped several times on the way home and she was acting better than she had since I bought her 3 yrs ago.

I went out and tried to start her yesterday morning and she said, "I will do everything as normal, EXCEPT turnover!!" So, I got out and checked the battery (12.8V), checked the terminals and tried again... No luck even attempting to turn over......

I went away to ponder for a bit (read cuss & shout) and then returned and tried again, and she started right up!! So I am a happy guy.

She started normally the next few times I needed her, but I noticed the backup camera did not always actuate as I placed her in reverse. Sometimes YES - sometimes NO - weird...

So I discussed this with a few co-workers today and they immediately suggested the Neutral Safety Switch may be crapping out. But, this would not explain the backup camera failing to actuate.

After a little more "pondering" this evening I went out and started experimenting (read guessing) and noticed that when I moved the shifter from Park to Reverse, the (R) did not illuminate on the center console and the backup camera did not actuate. I moved the shifter a little further down towards Neutral (slightly out of the (R) detent) and the (R) illuminated and the backup camera operated as normal. As I moved the shifter around the J-tree, the (D) illuminated, but the (4) would not - only the (3) and (2). So I moved the shifter back to Park, but the (P) did not illuminate until I went back down to (D) and then back up to Park.

During a few more cycles I noticed that sometimes everything hit right on the money and sometimes not. The (P), (R), (N), (D),(4), (3) and (2) would hit properly sometimes and sometimes not - the (3) and (2) always lit, but the (3) would sometimes lite in the (4) position and when this happened the (2) would lite in the (3) position....

When I picked up my car after the aforementioned repairs, the mechanic who did the work stated that they had to drop the sub-frame a little to access the rear CAT and I am now wondering if maybe they could have stretched the shifter cable to a point where it is not functioning as it did before the work. I am hoping it is just an adjustment issue and not the shifter assembly failing!

I checked the DTC and only got my standard P1000 code that I have gotten since I bought the car, but my reader may not be able to retrieve any other codes other than Pxxxx, and I am not sure if this problem would even throw a code...

I would appreciate any feedback/ideas from the group on the possible cause(s) of the coincidental problem with the shifter positioning after the maintenance that was performed.

 

All these TSBs can be found somewhere on this forum and GUS has them on his sight.

bob

 

Thanks for the response Motor, I am trying to figure out if it is even possible that the shifter cable could have been deformed/streched during the maintenance performed, or if it is more likely that it is simply a coincidence that the the problem showed up at this time...

My first action is going to be to figure out if it is a Transmission Range (TR) sensor issue, if the Selector Lever Cable needs adjustment, or if the J-Gate is failing. The TSB you provided was right on point for the cable adjustment - THANKS!

 

So, I took it out for a spin and received a Powertrain Malfunction light while driving. When this occurred, I looked down and observed that the "D" was not illuminated even though I was clearly in Drive and doing about 50 MPH. I pulled over and moved the selector through all positions and none would illuminate even though I could feel the transmission shift to each position correctly as I moved the selector thru the positions.

I placed the selector in Park, pulled the DTCs and received only a P1000 code. I reset the code - the Powertrain Malfunction light cleared and the "P" came back on as it should be. Additionally, each position illuminated properly as I shifted around the "J". I did not receive another Powertrain Malfunction light for the rest of the test drive, the "D" stayed illuminated while driving and the "N/R/P" all illuminated as I passed them while placing the car into park.

I am guessing that the Transmission Range Sensor (TSR) contains the circuit to illuminate the selector position lamps in each position and if the TSR is going bad (failing intermittently) it may fail to illuminate the selector position lamps properly - even if it fails while driving - and creates a Powertrain Malfunction signal. I am guessing that a bad TSR would also explain the failure to always start in Park, especially if the "P" lamp is not lit before an attempt to start because the ECM is not aware that the transmission is in the proper position.

Finally, it seems to me that once the Powertrain Malfunction light illuminates, it locks out the TSR and keeps any selector position lamp from illuminating until the Malfunction is cleared with an OBDII reader. Am I totally confused on what is happening?????

 

Info for your JATCO gearbox.

bob

 

Great info here - Thanks Bob!

From the manual you provided (Section 4.4) - "The range sensor is monitored by the TCM for loss of signal and multiple gearshift positions selected at the same time (indicating a short circuit in the harness). The presence of a crank signal from the ECM is also checked when the vehicle is not in park or neutral. If any of the conditions persist for longer than a defined period then a failure judgement is made. If the failure is detected on two consecutive drive cycles, the DTC is logged."

IF my OBDII reader had ever shown a P0706 code it would have simplified this post considerably. However, it does not show any DTCs. Now it seems apparent that the problem is not continuous (Seen once to trigger the Powertrain Malfunction, but not seen two or more consecutive times to log a DTC) and is either (In order of expense/difficulty):

(1) The TRS connector is suspect - disconnect clean and reconnect connector JB156;
(2) The TRS itself is failing and needs replacement;
(3) Intermittent short in the wiring harness outside the TSR;
(4) Failing TCM

Now I think I have a better understanding of my situation...

 

Well, well, well.... Killed the first three diagnostic checks at the same time....

(1) Check connector JB156..

I found that the previous owner obviously had a problem with the "Neutral Safety Switch" part of the range sensor, so he simply cut the Brown (N) input wire to the sensor and jumped it to the Black (B) output wire, thus bypassing the "P"/"N" safety function of the sensor (He did not even tape over the splice he had made --- sheeze! --- How I love working on a previously owned vehicle!!).

(2) The TRS itself is failing and needs replacement (Yep!)
(3) Intermittent short in the wiring harness outside the TSR (Yep!)

Rather than leave the jumped wires in place, I restored the harness to its intended condition and ordered a used TSR on EBay. She will sit safely until next weekend when I get the replacement part....

Will not know if this ultimately solves all of the shifter position illumination issues until, but it is a start.

 

I ordered a replacement Transmission Range Sensor (TRS) because I believed that the Neutral Safety Switch (NSS) portion of the sensor had gone bad. The reason I believed that the NSS had gone bad was due to the fact that I found that the Brown (N) wire to the TRS had been cut and jumped to the Black (B) wire in the harness before connector JB156.



I restored the wiring harness to original (Brown-Brown) and taped over the bare portion of the Black wire. After restoring the wiring harness to original, the car would not attempt to energize the starter - Obviously the NSS was bad and there was no connection being made inside the NSS when in P or N....

I replaced the TRS this evening and performed an adjustment check on the sensor I.A.W. the JTIS and all pins tested as expected (Table below of allowed values)


After putting everything back together, I got into my Jag, placed the ignition to position II and rechecked each shifter position for illumination - All positions illuminated as expected.

I went to start my newly repaired Jag and.... Nothing - no attempt to energize the starter.... What The Heck!! So, I took the battery & box back out, undid JB156 and tested everything again. After I finished - got the same result - all positions lit, no attempt to start......

Knowing the definition of insanity, I stopped a moment to ponder. I took the old TRS and tested it. I found that the old TRS passed all of the functional tests!!

I looked back at the "As Found" photos I had taken (attached above) and noticed that the HOT (+12V) Brown wire from the switched ignition harness was the one that had been cut lose and left to hang. The dead (NSS) side Brown was the one spliced into the Black wire from the NSS to the ECM Starter Circuit. This created the dead loop electrical circuit shown below.


Note: Both Fig. 04.1 (Early models - aka Mine) & Fig. 04.2 (Later Models) are identical for the NSS...

Earlier I thought that the "HOT" side Brown wire had been jumped to the Black NSS output to the ECM.

So now I have to ask, "How is it possible that this has worked for the past 3+ years?"

There would be no voltage supplied to the ECM Starter Circuit that requires +12V on pin 5 of JB145 at the ECM to function, I believe.



Tomorrow I will continue the quest and removed the repair I had made earlier (e.g. remove +12V from Pin 10 of JB156, test Pin 6 for +12V with the gear selector in P/N and ignition in position II. Then see if there is still +12V on pin 6 when in all other gears, and finally try to figure out how this could possibly work, based on the diagrams that show how it is supposed to work. If I have +12V on pin 6 without supplying voltage to Pin 10, I will have to track down where the +12V is coming from, since it must be between JB156 and JB145 with no other interfaces (unless they jumped it with +12V for some reason) - or the ECM is somehow supplying the voltage???

Why does it work without +12V on pin 10 but does not work with +12V supplied to pin 10 as designed?

 

If it seems impossible - it probably is... If I could delete my prior posts on this subject to hide my embarrassment I probably would.

Another look at my situation reveals that, where I thought Pin 6 and Pin 10 on JB156 were jumped, it is actually Pin 10 and Pin 8 were jumped - thus effectively creating an ECM Starting Circuit shorted to ground when in "P" or "N" instead of +12V supplied to the Starting Circuit, as designed.




This leads me to believe that there is a problem with the ECM starting circuit (within the ECM itself).

I have found a group that will rebuild the ECM for $250. Supposedly requiring no reprogramming after repair. ECM Repair | Engine Control Unit Repair

Has anyone tried this route? It seems at least as cost effective as the option of buying a used ECM and taking it to a dealer to reprogram or buying an ECM, instrument cluster, and transponder key all from the same donor vehicle to eliminate the need for reprogramming.

 

So the original problem of "Shifter position indication wanders" ended up being a failing shifter cable - replaced the cable and problem gone...

The other problem found with the Neutral Safety Switch and ECU Starting Circuit is within the ECU and I have sent the ECU off for repair. I could have left the Starting Circuit shorted to ground, but I could not ignore a known problem that is repairable......