I look for instruction on how to do the new revised wiring for the vcm an can not find any videos at all i just put another tranny in an i dont want this to destroy it please any help will do

 

What are you talking about??? Revised wiring??? What is the purpose??? Where did you hear of it???

 

Its the revised wiring for the faulty ground that cause transmission problems i found a step by step pictured how to ...but not on this site or forum its needed in alot of years mines a 96

 

Follow the procedure given in the TSB below. Note that if you have PCM P/N 16244210, then this TSB does not apply to your vehicle. I read it as being applicable to only a partial year of 1996.

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00-07-30-026 - (12/21/2000) Automatic Transmission 1-2and/or 2-3 Upshift Slip/Flare, No 3rd or 4th gear, Launch Shudder (Revise VCMWiring)
1996 Chevrolet and GMC C/K, S/T, M/L, G1, G2, P3 Models
1996 Oldsmobile Bravada
with VCM and 4L60-E (M30) or 4L80-E (MT1) Automatic Transmission

This bulletin is being reissued to ensure that correct procedures are followedfor this condition. Please discard Corporate Bulletin Number 66-71-03A (Section7 -- Automatic Transmission).

Condition
Some owners may comment that the automatic transmission has either a slip orflare on the 1-2 and/or 2-3 upshift, or no 3rd or 4th gear, or launch shudder.Upon investigation, the technician may find a DTC P1870 stored in the VCM.

Cause
A poor internal ground between the two circuit boards of the VCM may cause theVCM to command erratic line pressure at the pressure control (PC) solenoidvalve.

Correction
Using harness jumper wire and instruction kit, P/N 12167310, revise the wiringharness at the VCM connector. Corrections were made to the VCM beginning2/14/96. The corrected VCMs are identified with service number 16244210 on theVCM identification label.

Procedure
The following is a summary of the instructions included with the service kit:
1. Remove the negative terminal from the battery.
2. Move the wire located at connector J3 (WHITE/GREY/CLEAR), pin 18 toconnector J1 (BLUE), pin 23.
3. Install the jumper wire between connector J2 (RED), pin 26 and connector J3(WHITE/GREY/CLEAR), pin 18.
4. Install the tag included in the kit around the VCM wiring harness. This tagnotes that the wiring harness has been modified.
5. Reconnect the negative battery terminal.

Road test to verify that the condition has been corrected. If any of thefollowing conditions are noted, the transmission should be repaired or replacedusing the most cost effective method. Canadian dealers should repair thetransmission.
1. Transmission fluid oxidation or excessive sediment.
2. Transmission slip or flare after this service fix is performed.
3. DTC P1870 is stored on a 4L60-E (M30).

The following tools are available from Kent-Moore (1-800-345-2233) for use inremoving and relocating the VCM wires:
1. J 41758 Terminal Tool; used to remove the wire from the VCM connector.
2. J 41759 Punch; used to punch a new hole through the connector seal.

Parts Information
Part Number: 12167310
Description: Harness Jumper Wire Kit
Qty: 1

 

I realize this is an old thread, but I think this might be the TSB the OP is referring to. It looks very similar to the one posted above. I'm going to be trying it soon. A pictorial of one man's DIY repair can be found here: https://chevroletforum.com/forum/sil...-update-39893/ The pictures are blury, but read in conjunction with the TSB below, the procedure makes sense. I've got the hesitation and periodic stalling with the P0122 code showing up once in a while. I've changed out my fuel tank sensor, so I'm guessing it may be the VCM ground issue, which I have suspected since I got the truck. I also picked up a 96 VCM from ebay for $25 that has the revised part number (from Les' post) and will likely try the swaptronics first. Mine is an early 1996 (I think with a 12/95 build date), so it likely has the old VCM. I'll be thrilled if this helps!.

INTERMITTENT ENGINCE LOW POWER HESITATION AND/OR STALL #66-65-06 - (May 24, 1996)

SUBJECT: INTERMITTENT ENGINE LOW POWER, HESITATION AND/OR STALL, DTCS P0107, P0122, P1107, P1122, P1406 (REPLACE FUEL TANK PRESSURE SENSOR)

MODELS: 1996 CHEVROLET AND GMC S/T MODELS 1996 OLDSMOBILE BRAVADA WITH 4.3L ENGINE (VINS W, X - RPOS L35, LF6)

CONDITION:

AN OWNER MAY REPORT INTERMITTENT LOW ENGINE POWER, HESITATION AND/OR STALL, AND THE MALFUNCTION INDICATOR LAMP (SERVICE ENGINE SOON LIGHT) ON. ONE OR MORE OF THE FOLLOWING DTC'S MAY BE STORED IN THE VCM. P0107 (MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOW VOLTAGE), P0122 (THROTTLE POSITION SENSOR CIRCUIT LOW VOLTAGE), P1107 (MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT INTERMITTENT LOW VOLTAGE), P1122 (THROTTLE POSITION SENSOR CIRCUIT INTERMITTENT LOW VOLTAGE), P1406 (EXHAUST GAS RECIRCULATION VALVE PINTLE POSITION CIRCUIT).

CAUSE:

THERE CAN BE TWO POSSIBLE CAUSES. FIRST, A SHORTED FUEL TANK PRESSURE SENSOR CAN CAUSE THE VCM 5 VOLT REFERENCE VOLTAGE SIGNAL TO BE LOW (BELOW 4 VOLTS). SECOND, A POOR INTERNAL GROUND BETWEEN THE TWO CIRCUIT BOARDS OF THE VCM CAN CAUSE THE VCM TO INCORRECTLY MEASURE THE VOLTAGE AT THE THROTTLE POSITION SENSOR AND THE EGR PINTLE POSITION SENSOR.

CORRECTION:

USE THE FOLLOWING SERVICE PROCEDURE TO DIAGNOSE AND CORRECT THE CONDITION.

SERVICE PROCEDURE:

1. CHECK FOR VCM 5 VOLT REFERENCE SIGNAL AT A CONVENIENT LOCATION SUCH AS A VCM CONNECTOR. IMPORTANT: BOTH VCM REFERENCE LINES ARE INTERNALLY CONNECTED. IF THE 5 VOLT REFERENCE VOLTAGE VALUE IS BELOW 4 VOLTS, THEN CONTINUE WITH STEP 2. IF THE VALUE IS ABOVE 4 VOLTS, PROCEED TO STEP 6. 2. ISOLATE THE FUEL PRESSURE SENSOR AND/OR RELATED WIRING, BY OPENING CONNECTOR C199, A SIX WAY MICRO-PACK CONNECTOR LOCATED IN THE ENGINE COMPARTMENT BY THE LEFT FRONT (DRIVER'S SIDE) INNER WHEEL FENDER AREA, AND RECHECK VCM 5 VOLT REFERENCE VOLTAGE. 3. IF THE VCM 5 VOLT REFERENCE VOLTAGE IS NOW GREATER THAN 4 VOLTS, THE FUEL TANK PRESSURE SENSOR AND/OR RELATED WIRING IS THE LIKELY FAULT. PROCEED TO STEP 4. IF THE 5 VOLT REFERENCE LINE STILL SHOWS LESS THAN 4 VOLTS, THE FUEL TANK PRESSURE SENSOR AND CIRCUIT IS NOT THE CAUSE. PROCEED TO STEP 6. 4. RECONNECT CONNECTOR C199. 5. DISCONNECT THE FUEL PRESSURE SENSOR CONNECTOR AND RECHECK THE VCM 5 VOLT REFERENCE VOLTAGE. IF IT IS ABOVE 4 VOLTS, REMOVE THE FUEL PRESSURE SENSOR AND TEST IT BY CHECKING RESISTANCE AT EACH POSSIBLE COMBINATION OF SENSOR TERMINALS. IF ANY COMBINATION IS LESS THAN 800 OHMS, THE SENSOR SHOULD BE REPLACED. PROCEED TO STEP 7. 6. INSTALL HARNESS JUMPER WIRE, P/N 12167310.

THE FOLLOWING IS A SUMMARY OF THE INSTRUCTIONS INCLUDED WITH THE SERVICE KIT: A. REMOVE THE NEGATIVE TERMINAL FROM THE BATTERY. B. MOVE THE WIRE LOCATED AT CONNECTOR J3 (WHITE/GRAY/CLEAR), PIN 18 TO CONNECTOR J1 (BLUE), PIN 23. C. INSTALL THE JUMPER WIRE BETWEEN CONNECTOR J2 (RED), PIN 26 AND CONNECTOR J3 (WHITE/GRAY/CLEAR), PIN 18. D. INSTALL THE TAG INCLUDED IN THE KIT AROUND THE VCM WIRING HARNESS. THIS TAG NOTES THAT THE WIRING HARNESS HAS BEEN MODIFIED. E. RECONNECT THE NEGATIVE BATTERY TERMINAL. IMPORTANT: IF THE VEHICLE IS EXPERIENCING ANY TRANSMISSION SHIFTING CONCERNS, REFER TO SERVICE BULLETIN 66-71-04. 7. IF THE CONDITION IS NOT CORRECTED, REFER TO SECTION 3B OF THE SERVICE MANUAL FOR DIAGNOSIS OF EACH STORED DTC STARTING WITH LOWEST CODE. 8. CLEAR ALL STORED DTCS IN THE VCM AND ROAD TEST BEFORE RETURNING THE VEHICLE TO THE OWNER.

THE FOLLOWING TOOLS ARE AVAILABLE FROM KENT-MOORE (1-800- 345-2233) FOR USE IN REMOVING AND RELOCATING THE VCM WIRES: -J41758 TERMINAL TOOL: USED TO REMOVE THE WIRE FROM THE VCM CONNECTOR. -J41759 PUNCH: USED TO PUNCH A NEW HOLE THROUGH THE CONNECTOR SEAL.

PARTS INFORMATION:

P/N DESCRIPTION QTY 16196060 SENSOR - FUEL TANK PRESSURE 1 12167310 HARNESS JUMPER WIRE KIT 1

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

 

Plugged in the new computer and problems seem to be resolved. No more rough idling, racing tach after putting vehicle into park or torque converter lockup hunting. Time will tell if my random stalling issue is fixed. The only problem is that now my ABS light is on. So, I presume that some change got made to the ABS from the early 1996 model to the later 1996 models so that the computer is not seeing what it expects to see or something is wrong in my ABS system. Next time I'm at a junk yard, I'll pick up a computer connector and make the jumper wire sold in GM p/n 12167310 and put the old computer back in and see what happens. From what I understand, its a single wire with two connectors that plug into the computer's wiring connectors and it sells for over $60.

This is a very frustrating problem that is complicated by the fact that only a few month's worth of 1996 vehicles were affected. I've see a lot of old posts on forums where people with 1996 models have the TPS codes or EGR codes and never get their issues resolved. I'm betting a good number are this computer ground problem, but that so few cars were affected that there is not the depth of knowledge about the problem in the internet DIY community. Even the TSB for the transmission issues doesn't cross reference the earlier TSB or mention stalling and the DTCs being caused by the bad computer ground. If I were to buy another S10/Blazer, I would make sure that it was 1998 or later. At least it would have two air bags and hopefully GM would have worked through some of its growing pains with the new OBDII technology. I'm putting this information out there so that someone else with electrical gremlins in their 1996 S10 or Blazer or Bravada might stumble across it and find a solution.

 

I did the ground wire update this morning. Took about 30 minutes. I wound up going to the junk yard and getting a connector out of a vehicle to use in place of the $60 GM factory wire. I removed two wires from the junk yard connector and soldered them together. The computer has 5 connectors. You've got to get into the clear/white, blue and red. Fortunately, they all still have a lot of flex left in the plastic and I didn't come close to breaking anything. It's pretty self explanatory, but you've got to open up the grey connector housing by prying open the three tabs holding it together. Once its open, you have to remove the clear/blue/red cover over the pin housing. These cover hold the "keepers" down which keep the pins from pushing out. Once you remove the cover by pushing in the tabs on the sides, you gently pry back the keeper reed with a finger nail and pull the wire out the back side of the connector. Pin 18 on the clear/white connector is the only one you have to pull out. Then its just a matter of pushing the appropriate connector in the appropriate hole. The green moisture barrier is pre drilled, so you don't have to make new holes. I pushed the pins in with a pair of needle nose pliers. Putting back in my original computer with this wiring upgrade solved my ABS light. And going this wire route was a lot easier and cheaper than having the new computer flashed to my VIN. I hope this helps out the next guy.

The following are the problems that this repair permanently solved for me: periodic TPS and EGR codes, typically low voltage codes; ABS and brake light coming on randomly for a second or two with no codes; periodic stalling (the car would restart by the time I pulled over to crank the engine); truck slamming into gear after ABS and Brake light come on and car is restarted; racing, unsteady or high idle; torque converter lock up jumping in an out at about 40 mph.

 

Does anyone know the years affected by this? All I see is 96. I have a 2000 chevy s10 remanufactured transmission we put in and having same erratic shifting and abs lights is on.

 

The tsb says 96 and they were aware of the issue in 96 so I'm very doubtful that it went on to 2000