What does ECS32 refer to in the attached wiring diagram? I cannot find a location referenced in the wiring guide.
Does the “s” mean that it is a wire splice?

 

Yes, splices are graphically denoted in the schematics by a dot at the cable junction point and they are given a circuit reference code.
They can either be just a simple splice (the joining of one wire to another) or a splice (where an additional wire is being added).
They are typically individually insulated and nestled within the loom, so locating one generally means unwrapping a portion of loom to expose them.

 

Check the resistance across that splice by testing from the connectors on each end. Don't pull the loom apart at first because it is unlikely to be the splice that is causing a problem.

 

Great advise, thank you!
Still looking for an issue with SCP+ short to battery. Voltage is 9 to full battery voltage. (Test pin 2 and 16 of the ODB port ) Rather put out at this point as I completely replaced the CAN and the SCP bus with brand new shielded wire that is run directly to each module plug as well as the CAN connection to the ECM. Honestly can’t figure where the current is coming from; the only way I can get rid of the current is by disconnecting the grey 10 pin RF1 plug (located on the right end of the dash) that apparently powers the ignition and the ODB plug. This after disconnecting every plug and module remotely related to the SCP bus as well as several plugs and the ECM which produced no visible effect to the meter until I disconnected RF1. The reason this is my current priority is that the car starts and runs for 10-20 seconds then dies out due to lack of fuel pressure ostensibly because the ECM is not communicating to tell the REM to continue to power the fuel pump after the initial key on. I cannot reliably read ANY of the SCP modules data but specifically, I cannot read see or read any data from the REM. The oscilloscope shows well formed data packets on the SCP +&- which I took as a positive sign after replacing the bus. I tested from both the ODB port and at the REM to confirm consistency. Oddly, the resistance on the SCP bus is 114 to 115 ohms which I am confused about but wrote off as my meter… but now am starting to question. There is no indication in the wiring diagram of where the resistors are positioned on the SCP bus to check.

This project has been on going for a year and a half. I took it to a specialist 4 months ago which turned out to be a $1400 waste of money and time.

 

 

Since pin 16 is B+ I would expect there to be a high voltage at pin 2. It would mean that there is a complete or partial ground circuit on SCP, which could easily be inconsequential leakage through the electronics. A short to battery would show up between pin 2 and 4 or 5 and show a high voltage reading.

 

As point of reference and delineation from the SCP bus; this attached screen capture of the oscilloscope is the current CAN bus from the ODB port.
Additional information:

• it is not the fuel pump or the wiring to the fuel pump. This has been definitely ruled out by me an another mechanic. The pump is brand new and the fuel lines, filter and the injectors have all been confirmed to be in tip top working order.

The latest codes that I can get access to are:

• P1638 — hence why I am pursuing the SCP+ pin test.

 

I am not sure why you are chasing SCP. P1638 is the CAN bus to IC. Your o-scope signals look good from many modules however you cannot see which ones are chatting properly. Can I assume you have checked CAN for 60 ohms and no short to B+ or ground?

 

You’re right of course. This new code just popped up. I am going to go out and confirm it again by clearing it and seeing if it returns immediately. It is possible that I created it when I disconnect plugs. You gave me an interesting idea however: check my logic please, each module is self contained and “contributes” data to the bus as well as reads data from the bus that is addressed to itself. If I remove the bus pins from the plug and reconnect… I should be able to read data from the module via the scope to confirm it is talking, correct?

 

Yes and no. Each module communicates when there is a space. There is no guaranteed order. You may not see a consistent 'empty' spot in the trace. What should pop up is a code when each is disconnected. Also don't forget they try for correct info a few times so a poor connection etc may only show up once in a while as a second read may have success.

 

I see. What would you tend to expect if you looked at the module from a bench test perspective? Reading just the pins coming off the module itself in isolation?

 

I would expect it not to communicate and go crazy with nothing connected. What was the original code and fault you were chasing down?

 

That’s kind of the problem here. I am not able to access the ECM to read the codes. However, I CAN see the live data from the ECM via the handheld iCarsoft computer. I can see the fuel pressure drop to zero after the car starts. When the fuel pump is hot connected to ground the car will run fine. None of the SCP modules other than the IC are accessible to the code reader. However I know that many of them, if not all of them, are working to some degree as the items they service are for the most part functioning. It is not the battery as I have between 12.5 and 14 volts depending on the amount of time I play with the system.

following up on pins and codes:
The p1638 code appears to be gone. It has not reset after I cleared the code.
odb pin 2 - 10 ignition off 3.2k ohms
2 - 16 ignition off 12.94 volts
2-16 ignition on 12.43 volts
2 - (4 or 5) ignition off 143 ohms
6 - 14 ignition off 60 ohms

 

Have you checked the mechatronic plug on the transmission to see if it is full of oil? Check 6 and 14 to B+ with ignition on. Should be less than 5v. Check each, 6 and 14, resistance to ground, with ignition off, should be greater than 10k ohms.

 

Will do that now… I think I have, and did notice oil but stupidly did not give it a thought as it is in an area that had a lot of oil filth from the engine… or so I thought. Thank You.

 

Cleaned the plug on the transmission. Had some oil but not particularly “full” of oil. But not dry either.

Check 6 and 14 to B+ with ignition on.
2.3 and 2.6 ohms respectively.

6 and 14, resistance to ground with transmission plug disconnect.
6 = 8.23k ohms
14 = 8.23k ohms

6 and 14, resistance to ground with transmission plug cleaned and reconnected.
6 = 4.89k ohms
14 = 4.89k ohms

 

You are checking 6 and 14 to B+ for voltage not resistance. If there is any B+ it would throw any resistance reading off. When you check 6 and 14 to ground the battery should be disconnected to stop any residual B+ throwing off the resistance reading. Check those again if you did not do as preceding.

 

So just retested;

Check 6 and 14 to B+ with ignition on.
14 - 16 = 10.06 volts
6 - 16 = 9.74 volts

6 and 14, resistance to ground with transmission plug cleaned and reconnected. Battery disconnected.
6 = 4.6k ohms
14 = 4.6k ohms

 

That tells you that there is a short/partial to B+ and apparently to ground on the CAN bus. The easiest next check is to remove the connector from the ABS module. It has a locking mechanism that also pushes it off the pins when you lift up on it. Since you have already taken the mechatronic connector off you may want to do that first and redo the tests you just completed. If the values go to proper values in either case you know it is module/connector related in ECM, ABS or TCM. With only mechatronic off it would be the TCM or connector causing the problem. The connector still may be contaminated with oil to give those readings.

 

Removed the TCM plug and ran the test again:
Check 6 and 14 to B+ with ignition on.
6 - 16 = 2.33 volts
14 - 16 = 2.66 volts

6 and 14, resistance to ground Battery disconnected.
6 = 8.22 k ohms
14 = 8.22 k ohms

Removed the TCM and the ABS plug and ran the test again:
Check 6 and 14 to B+ with ignition on.
6 - 16 = 9.65volts
14 - 16 = 10volts

6 and 14, resistance to ground with Battery disconnected.
6 = 117K ohms
14 = 177K ohms