Substitute for Thinkcar Thinktool Pros Bi-Directional Scanner Full Systems Diagnostic Scan Tool

jeff6times7

New Member
Joined
Nov 21, 2023
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24
Location
Texas
I might have run out of patience trying to diagnose a crank no start problem with my 2002 Wranger Sport (4L I6).

I watched Ivan diagnose a seemingly undiagnosable problem here. He included a link in his summary to a diagnostic tool that Amazon says is not available. I saw others at Amazon (e.g., this) but before I spend a lot of money on a tool, I was hoping someone here might be able to recommend a substitute for the one Ivan cited.

Regarding my specific problem, In summary, I had a P0505 that I tried to reconcile by cleaning the Idle Air Control intake as Jerry mentioned. I drove it for about a half mile and the engine died. It cranks but won't start.

I bypassed the fuel pump relay and it delivers about 43 psi. When I shut it down, the rail holds pressure. So, I don't think it's a fuel pump problem.

I pulled the ignition rail and tested for spark to the block. No spark.

When I separated the crankshaft position sensor connector and tested for continuity between the B and C poles, I got infinite resistance. I got some resistance between A and B poles which I think is normal. I think the A pole is for 5V supply and B is the common ground. I know that doesn't prove a whole lot. In fact, I'm not feeling confident about anything after watching Ivan's video other than feeling like I need to buy a good diagnostic tool.

The bottom line is that it seems really wasteful to buy a replacement part without knowing how to scientifically and completely test that suspicious part.

I've looked at the 2002 TJ Service Manual and the list of inputs to the PCM during engine warm-up mode (open loop mode) is daunting: crankshaft position sensor, intake manifold air temp sensor, map sensor, throttle position sensor, camshaft position sensor, and others.
 
I should mention that after cleaning the throttle body and clearing the P0505, there are now no codes listed. I guess I'm not surprised considering that it only cranks.
 
I might have run out of patience trying to diagnose a crank no start problem with my 2002 Wranger Sport (4L I6).

I watched Ivan diagnose a seemingly undiagnosable problem here. He included a link in his summary to a diagnostic tool that Amazon says is not available. I saw others at Amazon (e.g., this) but before I spend a lot of money on a tool, I was hoping someone here might be able to recommend a substitute for the one Ivan cited.

Regarding my specific problem, In summary, I had a P0505 that I tried to reconcile by cleaning the Idle Air Control intake as Jerry mentioned. I drove it for about a half mile and the engine died. It cranks but won't start.

I bypassed the fuel pump relay and it delivers about 43 psi. When I shut it down, the rail holds pressure. So, I don't think it's a fuel pump problem.

I pulled the ignition rail and tested for spark to the block. No spark.

When I separated the crankshaft position sensor connector and tested for continuity between the B and C poles, I got infinite resistance. I got some resistance between A and B poles which I think is normal. I think the A pole is for 5V supply and B is the common ground. I know that doesn't prove a whole lot. In fact, I'm not feeling confident about anything after watching Ivan's video other than feeling like I need to buy a good diagnostic tool.

The bottom line is that it seems really wasteful to buy a replacement part without knowing how to scientifically and completely test that suspicious part.

I've looked at the 2002 TJ Service Manual and the list of inputs to the PCM during engine warm-up mode (open loop mode) is daunting: crankshaft position sensor, intake manifold air temp sensor, map sensor, throttle position sensor, camshaft position sensor, and others.

When checking for continuity you have to do it from the end of the sensor plug to the end of the PCM plug not between the wires on the plug, I believe that's why you're getting infinite resistance.

For Example: One end would be on #1 on sensor plug while the other end would be on #8 on the PCM plug.
1701112737620.png


1701112672510.png


Do you have SKIM on your TJ? (Grey or Black Key)
 
When checking for continuity you have to do it from the end of the sensor plug to the end of the PCM plug not between the wires on the plug, I believe that's why you're getting infinite resistance.

For Example: One end would be on #1 on sensor plug while the other end would be on #8 on the PCM plug.
View attachment 477578

View attachment 477575

Do you have SKIM on your TJ? (Grey or Black Key)

The key is grey so there's no batter to go bad. I checked the pins on the sensor end of the unit. I wasn't checking the other end that connects to the PCM. I've read and watched others say that if pins B and C do NOT have infinite resistance, then the CPS is bad. So, having infinite resistance between B and C is good. But I don't think that proves that the CPS is good. Right?
 
Wow. There IS a "no key inserted" icon on the dash. If there is no battery in this grey key, then what's going on?

Charles said a couple of years ago that the grey key can't go bad.
 
The key is grey so there's no batter to go bad. I checked the pins on the sensor end of the unit. I wasn't checking the other end that connects to the PCM. I've read and watched others say that if pins B and C do NOT have infinite resistance, then the CPS is bad. So, having infinite resistance between B and C is good. But I don't think that proves that the CPS is good. Right?

Well grey key would mean that your TJ comes with a SKIM module. We're troubleshooting another member's vehicle and both the symptoms sounds the same, TJ wont run and PCM shows no engine codes.

https://wranglertjforum.com/threads/tj-starts-but-then-dies.74717/

Wow. There IS a "no key inserted" icon on the dash. If there is no battery in this grey key, then what's going on?

Charles said a couple of years ago that the grey key can't go bad.

Correct i believe its a RFID chip in the key, what goes bad is the module that's on the steering column by where you insert the key
 
Well grey key would mean that your TJ comes with a SKIM module. We're troubleshooting another member's vehicle and both the symptoms sounds the same, TJ wont run and PCM shows no engine codes.

https://wranglertjforum.com/threads/tj-starts-but-then-dies.74717/



Correct i believe its a RFID chip in the key, what goes bad is the module that's on the steering column by where you insert the key

Correct re: the keys. If the SKIM module failed, you'll have to go to the dealership to get a new one programmed. I'd check for wiring issues on the SKIM first.
 
Unfortunately, I have only one key.

In that case, (as Mr. Blaine advises in the thread I linked) take it to the dealership. Best case, they program a new key and/or module. Worst case, they can confirm that the module and key are working and you can check that off the list.

Usually the cheapest option is to have your PCM reflashed to remove the SKIM. Otherwise it involves towing your TJ to the dealership for them to rework the SKIM assuming the module is still available from MOPAR.

The SKIM is actually pretty good theft protection. Personally, I would look at getting it working or ruling it out as the cause.