Diagnostic tree for MAP sensor of '94 Caddillac STS

[Monaco500]

Hey guys,

Still trying to figure out my '94 STS. Does anyone have a scan of the diagnostic tree for the MAP sensor available for download? I keep getting the PO71 code after the car surges and dies...

Thanks for your help!

Eric

[Logan]

Hey guys,

Still trying to figure out my '94 STS. Does anyone have a scan of the diagnostic tree for the MAP sensor available for download? I keep getting the PO71 code after the car surges and dies...

Thanks for your help!

Eric

There were some goofy '94 PCMs......PO71.....I would be surprised it would not have shown up sooner....but here is the bulletin....

HARSH CHUGGLE/MISS/HESITATION DTC PO71 (CHECK/REPAIR DTC) #47-65-06 - (May 12, 1994)

SUBJECT: HARSH CHUGGLE, SURGE, MISS, HESITATION ACCOMPANIED BY A HISTORY DIAGNOSTIC TROUBLE CODE PO71 (CHECK/REPAIR PER DTC)

MODELS: 1993 CADILLAC ALLANTE, ELDORADO COUPE AND SEVILLE SEDAN 1994 CADILLAC ELDORADO, SEVILLE AND CONCOURS WITH 4.6L ENGINE (VINS Y AND 9 - RPOS LD8 AND L37)

CONDITION:

SOME OWNERS MAY EXPERIENCE ENGINE ROUGHNESS, HARSH CHUGGLE DURING HIGHWAY DRIVING, SURGE, MISS AND HESITATION WITH NO MIL OR MESSAGE AND A HISTORY DIAGNOSTIC TROUBLE CODE PO71.

CAUSE:

CODE PO71 SETS WHEN THERE IS A RAPID CHANGE IN MAP WITH NO CORRESPONDING CHANGE IN THE TP SENSOR OR RPM. A DTC PO71 MAY BE A SYMPTOM OF A DRIVEABILITY CONDITION SUCH AS BACKFIRE, STALL, OR LOSS OF POWER. A FALSELY SET DTC PO71 MAY BE CAUSED BY INTERNAL "NOISE" IN SOME NORTHSTAR PCMS INDUCED INTO THE INTERNAL PCM MAP CIRCUIT.

NOTE: ENGINE OIL NEAR OR ON MAP SENSOR IS A NORMAL CONDITION. MAP SENSORS SHOULD NOT BE REPLACED IF ENGINE OIL IS PRESENT.

CORRECTION:

THE NORTHSTAR'S PCM HAS BEEN REDESIGNED TO CORRECT THIS INTERNAL CIRCUIT "NOISE" CONDITION. TO DIAGNOSE AND REPAIR THE ABOVE CONDITIONS, PERFORM THE FOLLOWING PROCEDURES:

1. IF THE VEHICLE HAS MULTIPLE DIAGNOSTIC TROUBLE CODES AND DTC PO71, DIAGNOSE AND REPAIR THE **OTHER** DIAGNOSTIC TROUBLE CODES FIRST.

2. IF THERE WAS A BACKFIRE OR STALL, DIAGNOSE THAT CONDITION AS OUTLINED IN SECTION 6E-B OF THE SERVICE MANUAL.

3. IF THE VEHICLE IS A 1993 AND HAD A LOSS OF POWER AFTER AN EXTENDED HIGHWAY DRIVE, PERFORM THE PROCEDURES OUTLINED IN CORPORATE BULLETIN 216306 (GM OF CANADA 93-6-118; CADILLAC T-93-49 IN GROUP 6E).

4. IF THE VEHICLE IS A 1993, PERFORM THE PROCEDURES OUTLINED IN CORPORATE BULLETIN 316005 (GM OF CANADA 93-6-118; CADILLAC T-93-101 IN GROUP 6E).

5. IF THE VEHICLE HAS A HARSH CHUGGLE DURING HIGHWAY DRIVING, SURGE, MISS OR HESITATION ACCOMPANIED BY A HISTORY DTC PO71, INSPECT THE SERVICE PART NUMBER ON THE PCM. IF IT IS ONE OF THE PRESENT SERVICE PART NUMBERS LISTED BELOW, REPLACE THE PCM USING ONE OF THE APPROPRIATE **NEW** SERVICE PART NUMBERS LISTED BELOW.

6. IF THE PCM HAS THE NEW SERVICE PART NUMBER, FOLLOW THE APPROPRIATE SERVICE INFORMATION MANUAL PROCEDURES FOR DTC PO71 AND INSPECT THE MAP SENSOR CONNECTIONS AND CIRCUITRY.

PARTS INFORMATION:

PRESENT NEW DTC PO71 DESCRIPTION APPLICATIONS SERVICE P/N SERVICE P/N ----------- ------------ ----------- ------------- POWERTRAIN CONTROL MODULE 1993 V WITHOUT V4J 16159277 16207768 POWERTRAIN CONTROL MODULE 1993 V,E,K WITH V4J 16180517 16197429 POWERTRAIN CONTROL MODULE 1994 E/K + KSP 16196402 16197429

PARTS ARE EXPECTED TO BE AVAILABLE ON MAY 23, 1994.

[BodybyFisher]

That's great info Logan, as you can see from Monaco's thread here, he appears to be having the symptoms you describe:

http://caddyinfo.ipbhost.com/index.php?showtopic=8547

Thanks, Mike

[PAUL T]

Here it is in PDF format.

[PAUL T]

Send me a PM with your email address and I will send this PDF of the Diagnostic tree. I can not seem to send it any other way.

[Monaco500]

Hello everyone,

The next update on the POS STS:

I suspect that my MAP sensor error codes are the symptom but not the cause. I was thinking about this while blocking traffic on a major road last night after stalling out after stopping the car to run and errand on my way home from work. After stopping at Home Depot, I started the car and it started to surge. It died in the middle of the street, I coasted to the side, and tried to start the car. It would attempt to start, them immediately die. Then it wouldn't fire at all. I finally got it started after about 15 minutes. It ran extremely poorly, but I was able to keep it running long enough to get it out of the road. It was still surging. I then waited 2 hours, the car started up fine, and I drove for 35 minutes back home. Just to test, once I got home, I cleared all the codes, shut off the car, let it sit for 5 minutes, and started it again. Irratic idle, surging, stalling. Couldn't even put it in gear witout it dying. It reset the PO32, PO71, and PO95 codes.

The car will usually operate fine until it has been shut off, even for as little as 5 minutes. During that time, something happens that triggers the surging, irratic RPM, and stalling when it is started again. If the car sits just for a bit, even if the engine is still warm (190 degrees), all of the symptoms occur. It almost acts as if it had a carb and it were vapor locking. Could it be the fuel pressure regulator acting up, and when the car chokes, it results in the MAP giving irratic readings?

Thanks,

Eric

[BodybyFisher]

I can't help you with the code, POS

Have you looked at what Logan posted above? The symptoms look similar.

You replaced the PCM right? If you did, where did you get it? We recently had a member that replaced a PCM and the new one was bad. I would look toward the PCM. Was it aftermarket, new, used?

[Monaco500]

I can't help you with the code, POS

Have you looked at what Logan posted above? The symptoms look similar.

In addition, I forget, did you replace the PCM? If you did, where did you get it?

Yeah, the POS code is one that I came up with while sitting there blocking traffic for 15 min after the car stalled last night .

I replaced the PCM from www.autoecms.com, but it didn't solve the problem, so I returned it and put the original back in. Their "remanufactured" PCM was very dirty inside and was clearly not remanufactured.

I agree that if it is one of the recalled PCM's that the symptoms would have likely occurred earlier (the car has 140k), but I will check the serial number when I get home. If I need to replace it, I've learned my lesson and will get it from gmpartsdirect this time.

[PAUL T]

If the MAP sensor checks out. You could check the FPR, but I am still leaning toward bad PCM. Did You ever check your battery connections for tightness and corrosion?

[BodybyFisher]

If you have a bad PCM, you will get the kind of problems you have when its warmed up. I don't have time to seek them out but there are a LOT of posts on PCM problems. That your year has a quirkly PCM does not bode well either. Try the PCM tap test to see if you can cause the engine to stumble. I personally would substitute a known good PCM before I went any further.

Check all grounds in the area of the PCM and check the PCM connections for corrosion and a tight fit also.

[Monaco500]

If the MAP sensor checks out. You could check the FPR, but I am still leaning toward bad PCM. Did You ever check your battery connections for tightness and corrosion?

Yes, I replaced the negative cable with a new jumper cable to the frame. I cleaned both positive and negative terminals.

I guess I am still suspicious the problem is other than the PCM since I had identical symptoms with the replacement PCM, but I guess it is possible that they sent me a bad PCM with the same failure.

I have tried looking online for a '94 manual, but none are listed on Ebay. Does anyone have the sections 6D4 (ignition diagnosis, misfire) or 6EB posted to a thread? I guess I can try to get copies from the local Caddy dealership. Because I just replaced the MAP, after reading the Tree that paul sent me, I suspect that my problems are deeper than that... I'll go through the MAP testing procedure later tonight to be sure...

Thanks guys,

Eric

[Monaco500]

Hey guys,

Still trying to figure out my '94 STS. Does anyone have a scan of the diagnostic tree for the MAP sensor available for download? I keep getting the PO71 code after the car surges and dies...

Thanks for your help!

Eric

There were some goofy '94 PCMs......PO71.....I would be surprised it would not have shown up sooner....but here is the bulletin....

HARSH CHUGGLE/MISS/HESITATION DTC PO71 (CHECK/REPAIR DTC) #47-65-06 - (May 12, 1994)

SUBJECT: HARSH CHUGGLE, SURGE, MISS, HESITATION ACCOMPANIED BY A HISTORY DIAGNOSTIC TROUBLE CODE PO71 (CHECK/REPAIR PER DTC)

MODELS: 1993 CADILLAC ALLANTE, ELDORADO COUPE AND SEVILLE SEDAN 1994 CADILLAC ELDORADO, SEVILLE AND CONCOURS WITH 4.6L ENGINE (VINS Y AND 9 - RPOS LD8 AND L37)

CONDITION:

SOME OWNERS MAY EXPERIENCE ENGINE ROUGHNESS, HARSH CHUGGLE DURING HIGHWAY DRIVING, SURGE, MISS AND HESITATION WITH NO MIL OR MESSAGE AND A HISTORY DIAGNOSTIC TROUBLE CODE PO71.

CAUSE:

CODE PO71 SETS WHEN THERE IS A RAPID CHANGE IN MAP WITH NO CORRESPONDING CHANGE IN THE TP SENSOR OR RPM. A DTC PO71 MAY BE A SYMPTOM OF A DRIVEABILITY CONDITION SUCH AS BACKFIRE, STALL, OR LOSS OF POWER. A FALSELY SET DTC PO71 MAY BE CAUSED BY INTERNAL "NOISE" IN SOME NORTHSTAR PCMS INDUCED INTO THE INTERNAL PCM MAP CIRCUIT.

NOTE: ENGINE OIL NEAR OR ON MAP SENSOR IS A NORMAL CONDITION. MAP SENSORS SHOULD NOT BE REPLACED IF ENGINE OIL IS PRESENT.

CORRECTION:

THE NORTHSTAR'S PCM HAS BEEN REDESIGNED TO CORRECT THIS INTERNAL CIRCUIT "NOISE" CONDITION. TO DIAGNOSE AND REPAIR THE ABOVE CONDITIONS, PERFORM THE FOLLOWING PROCEDURES:

1. IF THE VEHICLE HAS MULTIPLE DIAGNOSTIC TROUBLE CODES AND DTC PO71, DIAGNOSE AND REPAIR THE **OTHER** DIAGNOSTIC TROUBLE CODES FIRST.

2. IF THERE WAS A BACKFIRE OR STALL, DIAGNOSE THAT CONDITION AS OUTLINED IN SECTION 6E-B OF THE SERVICE MANUAL.

3. IF THE VEHICLE IS A 1993 AND HAD A LOSS OF POWER AFTER AN EXTENDED HIGHWAY DRIVE, PERFORM THE PROCEDURES OUTLINED IN CORPORATE BULLETIN 216306 (GM OF CANADA 93-6-118; CADILLAC T-93-49 IN GROUP 6E).

4. IF THE VEHICLE IS A 1993, PERFORM THE PROCEDURES OUTLINED IN CORPORATE BULLETIN 316005 (GM OF CANADA 93-6-118; CADILLAC T-93-101 IN GROUP 6E).

5. IF THE VEHICLE HAS A HARSH CHUGGLE DURING HIGHWAY DRIVING, SURGE, MISS OR HESITATION ACCOMPANIED BY A HISTORY DTC PO71, INSPECT THE SERVICE PART NUMBER ON THE PCM. IF IT IS ONE OF THE PRESENT SERVICE PART NUMBERS LISTED BELOW, REPLACE THE PCM USING ONE OF THE APPROPRIATE **NEW** SERVICE PART NUMBERS LISTED BELOW.

6. IF THE PCM HAS THE NEW SERVICE PART NUMBER, FOLLOW THE APPROPRIATE SERVICE INFORMATION MANUAL PROCEDURES FOR DTC PO71 AND INSPECT THE MAP SENSOR CONNECTIONS AND CIRCUITRY.

PARTS INFORMATION:

PRESENT NEW DTC PO71 DESCRIPTION APPLICATIONS SERVICE P/N SERVICE P/N ----------- ------------ ----------- ------------- POWERTRAIN CONTROL MODULE 1993 V WITHOUT V4J 16159277 16207768 POWERTRAIN CONTROL MODULE 1993 V,E,K WITH V4J 16180517 16197429 POWERTRAIN CONTROL MODULE 1994 E/K + KSP 16196402 16197429

PARTS ARE EXPECTED TO BE AVAILABLE ON MAY 23, 1994.

Thanks for the help, Logan.

I was a little confused by the Service part numbers for the PCM: My service number on the PCM is 16180517. Does this mean that it will need to be replaced? If so, replaced with which numbers?

Thanks,

Eric

[CaddyChris]

Hey guys,

Still trying to figure out my '94 STS. Does anyone have a scan of the diagnostic tree for the MAP sensor available for download? I keep getting the PO71 code after the car surges and dies...

Thanks for your help!

Eric

There were some goofy '94 PCMs......PO71.....I would be surprised it would not have shown up sooner....but here is the bulletin....

HARSH CHUGGLE/MISS/HESITATION DTC PO71 (CHECK/REPAIR DTC) #47-65-06 - (May 12, 1994)

SUBJECT: HARSH CHUGGLE, SURGE, MISS, HESITATION ACCOMPANIED BY A HISTORY DIAGNOSTIC TROUBLE CODE PO71 (CHECK/REPAIR PER DTC)

MODELS: 1993 CADILLAC ALLANTE, ELDORADO COUPE AND SEVILLE SEDAN 1994 CADILLAC ELDORADO, SEVILLE AND CONCOURS WITH 4.6L ENGINE (VINS Y AND 9 - RPOS LD8 AND L37)

CONDITION:

SOME OWNERS MAY EXPERIENCE ENGINE ROUGHNESS, HARSH CHUGGLE DURING HIGHWAY DRIVING, SURGE, MISS AND HESITATION WITH NO MIL OR MESSAGE AND A HISTORY DIAGNOSTIC TROUBLE CODE PO71.

CAUSE:

CODE PO71 SETS WHEN THERE IS A RAPID CHANGE IN MAP WITH NO CORRESPONDING CHANGE IN THE TP SENSOR OR RPM. A DTC PO71 MAY BE A SYMPTOM OF A DRIVEABILITY CONDITION SUCH AS BACKFIRE, STALL, OR LOSS OF POWER. A FALSELY SET DTC PO71 MAY BE CAUSED BY INTERNAL "NOISE" IN SOME NORTHSTAR PCMS INDUCED INTO THE INTERNAL PCM MAP CIRCUIT.

NOTE: ENGINE OIL NEAR OR ON MAP SENSOR IS A NORMAL CONDITION. MAP SENSORS SHOULD NOT BE REPLACED IF ENGINE OIL IS PRESENT.

CORRECTION:

THE NORTHSTAR'S PCM HAS BEEN REDESIGNED TO CORRECT THIS INTERNAL CIRCUIT "NOISE" CONDITION. TO DIAGNOSE AND REPAIR THE ABOVE CONDITIONS, PERFORM THE FOLLOWING PROCEDURES:

1. IF THE VEHICLE HAS MULTIPLE DIAGNOSTIC TROUBLE CODES AND DTC PO71, DIAGNOSE AND REPAIR THE **OTHER** DIAGNOSTIC TROUBLE CODES FIRST.

2. IF THERE WAS A BACKFIRE OR STALL, DIAGNOSE THAT CONDITION AS OUTLINED IN SECTION 6E-B OF THE SERVICE MANUAL.

3. IF THE VEHICLE IS A 1993 AND HAD A LOSS OF POWER AFTER AN EXTENDED HIGHWAY DRIVE, PERFORM THE PROCEDURES OUTLINED IN CORPORATE BULLETIN 216306 (GM OF CANADA 93-6-118; CADILLAC T-93-49 IN GROUP 6E).

4. IF THE VEHICLE IS A 1993, PERFORM THE PROCEDURES OUTLINED IN CORPORATE BULLETIN 316005 (GM OF CANADA 93-6-118; CADILLAC T-93-101 IN GROUP 6E).

5. IF THE VEHICLE HAS A HARSH CHUGGLE DURING HIGHWAY DRIVING, SURGE, MISS OR HESITATION ACCOMPANIED BY A HISTORY DTC PO71, INSPECT THE SERVICE PART NUMBER ON THE PCM. IF IT IS ONE OF THE PRESENT SERVICE PART NUMBERS LISTED BELOW, REPLACE THE PCM USING ONE OF THE APPROPRIATE **NEW** SERVICE PART NUMBERS LISTED BELOW.

6. IF THE PCM HAS THE NEW SERVICE PART NUMBER, FOLLOW THE APPROPRIATE SERVICE INFORMATION MANUAL PROCEDURES FOR DTC PO71 AND INSPECT THE MAP SENSOR CONNECTIONS AND CIRCUITRY.

PARTS INFORMATION:

PRESENT NEW DTC PO71 DESCRIPTION APPLICATIONS SERVICE P/N SERVICE P/N ----------- ------------ ----------- ------------- POWERTRAIN CONTROL MODULE 1993 V WITHOUT V4J 16159277 16207768 POWERTRAIN CONTROL MODULE 1993 V,E,K WITH V4J 16180517 16197429 POWERTRAIN CONTROL MODULE 1994 E/K + KSP 16196402 16197429

PARTS ARE EXPECTED TO BE AVAILABLE ON MAY 23, 1994.

Thanks for the help, Logan.

I was a little confused by the Service part numbers for the PCM: My service number on the PCM is 16180517. Does this mean that it will need to be replaced? If so, replaced with which numbers?

Thanks,

Eric

Yes, it's one of the numbers listed so it's BAD.

IF IT IS ONE OF THE PRESENT SERVICE PART NUMBERS LISTED BELOW, REPLACE THE PCM USING ONE OF THE APPROPRIATE **NEW** SERVICE PART NUMBERS LISTED BELOW.

I would get a new one as you said.

EDIT: Hey I reread this about 5x, I still don't understand either....sorry.

EDIT: Now i see, the new part numbers weren't available yet when this bulletin came out....that's what the blanks are. Your PCM needs to be replaced.!

[Monaco500]

Hey guys,

Still trying to figure out my '94 STS. Does anyone have a scan of the diagnostic tree for the MAP sensor available for download? I keep getting the PO71 code after the car surges and dies...

Thanks for your help!

Eric

There were some goofy '94 PCMs......PO71.....I would be surprised it would not have shown up sooner....but here is the bulletin....

HARSH CHUGGLE/MISS/HESITATION DTC PO71 (CHECK/REPAIR DTC) #47-65-06 - (May 12, 1994)

SUBJECT: HARSH CHUGGLE, SURGE, MISS, HESITATION ACCOMPANIED BY A HISTORY DIAGNOSTIC TROUBLE CODE PO71 (CHECK/REPAIR PER DTC)

MODELS: 1993 CADILLAC ALLANTE, ELDORADO COUPE AND SEVILLE SEDAN 1994 CADILLAC ELDORADO, SEVILLE AND CONCOURS WITH 4.6L ENGINE (VINS Y AND 9 - RPOS LD8 AND L37)

CONDITION:

SOME OWNERS MAY EXPERIENCE ENGINE ROUGHNESS, HARSH CHUGGLE DURING HIGHWAY DRIVING, SURGE, MISS AND HESITATION WITH NO MIL OR MESSAGE AND A HISTORY DIAGNOSTIC TROUBLE CODE PO71.

CAUSE:

CODE PO71 SETS WHEN THERE IS A RAPID CHANGE IN MAP WITH NO CORRESPONDING CHANGE IN THE TP SENSOR OR RPM. A DTC PO71 MAY BE A SYMPTOM OF A DRIVEABILITY CONDITION SUCH AS BACKFIRE, STALL, OR LOSS OF POWER. A FALSELY SET DTC PO71 MAY BE CAUSED BY INTERNAL "NOISE" IN SOME NORTHSTAR PCMS INDUCED INTO THE INTERNAL PCM MAP CIRCUIT.

NOTE: ENGINE OIL NEAR OR ON MAP SENSOR IS A NORMAL CONDITION. MAP SENSORS SHOULD NOT BE REPLACED IF ENGINE OIL IS PRESENT.

CORRECTION:

THE NORTHSTAR'S PCM HAS BEEN REDESIGNED TO CORRECT THIS INTERNAL CIRCUIT "NOISE" CONDITION. TO DIAGNOSE AND REPAIR THE ABOVE CONDITIONS, PERFORM THE FOLLOWING PROCEDURES:

1. IF THE VEHICLE HAS MULTIPLE DIAGNOSTIC TROUBLE CODES AND DTC PO71, DIAGNOSE AND REPAIR THE **OTHER** DIAGNOSTIC TROUBLE CODES FIRST.

2. IF THERE WAS A BACKFIRE OR STALL, DIAGNOSE THAT CONDITION AS OUTLINED IN SECTION 6E-B OF THE SERVICE MANUAL.

3. IF THE VEHICLE IS A 1993 AND HAD A LOSS OF POWER AFTER AN EXTENDED HIGHWAY DRIVE, PERFORM THE PROCEDURES OUTLINED IN CORPORATE BULLETIN 216306 (GM OF CANADA 93-6-118; CADILLAC T-93-49 IN GROUP 6E).

4. IF THE VEHICLE IS A 1993, PERFORM THE PROCEDURES OUTLINED IN CORPORATE BULLETIN 316005 (GM OF CANADA 93-6-118; CADILLAC T-93-101 IN GROUP 6E).

5. IF THE VEHICLE HAS A HARSH CHUGGLE DURING HIGHWAY DRIVING, SURGE, MISS OR HESITATION ACCOMPANIED BY A HISTORY DTC PO71, INSPECT THE SERVICE PART NUMBER ON THE PCM. IF IT IS ONE OF THE PRESENT SERVICE PART NUMBERS LISTED BELOW, REPLACE THE PCM USING ONE OF THE APPROPRIATE **NEW** SERVICE PART NUMBERS LISTED BELOW.

6. IF THE PCM HAS THE NEW SERVICE PART NUMBER, FOLLOW THE APPROPRIATE SERVICE INFORMATION MANUAL PROCEDURES FOR DTC PO71 AND INSPECT THE MAP SENSOR CONNECTIONS AND CIRCUITRY.

PARTS INFORMATION:

PRESENT NEW DTC PO71 DESCRIPTION APPLICATIONS SERVICE P/N SERVICE P/N ----------- ------------ ----------- ------------- POWERTRAIN CONTROL MODULE 1993 V WITHOUT V4J 16159277 16207768 POWERTRAIN CONTROL MODULE 1993 V,E,K WITH V4J 16180517 16197429 POWERTRAIN CONTROL MODULE 1994 E/K + KSP 16196402 16197429

PARTS ARE EXPECTED TO BE AVAILABLE ON MAY 23, 1994.

Thanks for the help, Logan.

I was a little confused by the Service part numbers for the PCM: My service number on the PCM is 16180517. Does this mean that it will need to be replaced? If so, replaced with which numbers?

Thanks,

Eric

Yes, it's one of the numbers listed so it's BAD.

IF IT IS ONE OF THE PRESENT SERVICE PART NUMBERS LISTED BELOW, REPLACE THE PCM USING ONE OF THE APPROPRIATE **NEW** SERVICE PART NUMBERS LISTED BELOW.

I would get a new one as you said.

EDIT: Hey I reread this about 5x, I still don't understand either....sorry.

EDIT: Now i see, the new part numbers weren't available yet when this bulletin came out....that's what the blanks are. Your PCM needs to be replaced.!

Chris,

Thanks for helping me figure out that post. Since my PCM service number is "on the list", what number should I be sure to get with the new one? When I ordered my replacement "remanufactured" PCM, they asked for the service number so they could match it. I guess that is no surprise why I had problems with the new one.

They said that they will replace that one, but I will need a new service number. Based on how dirty the old one was, I'm a bit nervous to use them again. If I eat the shipping/stocking fee with the last one I bought and go straight to GMPARTSDIRECT, will they know the replacement number that I will need for the '94 STS?

Thanks again guys,

Eric

[BodybyFisher]

This is an interesting dilemma. Its also interesting to note that Rockauto.com sells a Standard Motor Products Part #EM0517

16180517 (computer) for $85.79 plus the core for your car. I ASS_U_ME that part has been updated. Maybe a call to a dealer or Rockauto would help.

[Monaco500]

This is an interesting dilemma. Its also interesting to note that Rockauto.com sells a Standard Motor Products Part #EM0517

16180517 (computer) for $85.79 plus the core for your car. I ASS_U_ME that part has been updated. Maybe a call to a dealer or Rockauto would help.

Thanks for your research; Rockauto has a good price too.

I just sent their service department an e-mail; I think I'll call the Caddy dealer tomorrow.

I'll let you know what I find out...

[PAUL T]

This is an interesting dilemma. Its also interesting to note that Rockauto.com sells a Standard Motor Products Part #EM0517

16180517 (computer) for $85.79 plus the core for your car. I ASS_U_ME that part has been updated. Maybe a call to a dealer or Rockauto would help.

Thanks for your research; Rockauto has a good price too.

I just sent their service department an e-mail; I think I'll call the Caddy dealer tomorrow.

I'll let you know what I find out...

I have found that asking the Cadillac dealer parts guy if you could get a discounted price because you could get it on line at GMPARTSDIRECT for whatever amount and almost always I can get it cheaper at the dealer if you count the shipping costs. Haggle, in a nice way,and you will be surprised how much the price drops.

[CaddyChris]

Hey Eric,

No problem, I frequent the site often and try to help out when I can/when I have time. As far as the new part numbers, I think you are on the right track. Just make sure whoever you get the new PCM from that it is the updated one. Good Luck.

Chris

This is an interesting dilemma. Its also interesting to note that Rockauto.com sells a Standard Motor Products Part #EM0517

16180517 (computer) for $85.79 plus the core for your car. I ASS_U_ME that part has been updated. Maybe a call to a dealer or Rockauto would help.

Thanks for your research; Rockauto has a good price too.

I just sent their service department an e-mail; I think I'll call the Caddy dealer tomorrow.

I'll let you know what I find out...

I have found that asking the Cadillac dealer parts guy if you could get a discounted price because you could get it on line at GMPARTSDIRECT for whatever amount and almost always I can get it cheaper at the dealer if you count the shipping costs. Haggle, in a nice way,and you will be surprised how much the price drops.

Very true, I always find that whomever I am dealing with is looking for business and no price is really set in stone. Good idea to always negotiate.

[Monaco500]

Hey guys,

Here's the latest:

I contacted Mark at Rock Auto. He said that the EM0517 part number for the PCM was from a vendor, Standard Motor Company. He said that they did not have one available and that it can take a while to get an order through them. He continued to say that he has worked with SIA, a small company in Illinois, who also supplies/repairs PCM’s. Mark said that they list a part number (510517) for a PCM through SIA, but that they do not have one available.

He said that for $35.79 + a $15.00 fee that I can send them my PCM for reconditioning. I like the price, but fear that they won’t do much for that price. Especially when it only fails right after driving for a while.

I described the problems I am having and that the service bulletin from May of ’94 said that my PCM should be replaced (service # 16180517). He wasn’t familiar with the GM PCM’s, but said that a “remanufactured” should be corrected.

I then called the dealer. $266.03 + $67.50 core charge. In stock. The service department said that I should never buy a PCM from anywhere but GM. The price was non-negotiable. They suggested for $90/hr, that I bring the car in for dignostics.

So here’s the fork in the road. Should I:

1. Pay the $90/hr for diagnostics to see if they think it is my PCM or another problem, if it is, either have mine reconditioned or buy one from GM;

2. Send my PCM to SIA for reconditioning, hope that the PCM is the problem, and hope they fix the MAP circuit noise issue;

3. Cut my losses and just pay for the GM computer, hoping that the PCM is indeed the problem.

Thoughts?

Hey Eric,

No problem, I frequent the site often and try to help out when I can/when I have time. As far as the new part numbers, I think you are on the right track. Just make sure whoever you get the new PCM from that it is the updated one. Good Luck.

Chris

This is an interesting dilemma. Its also interesting to note that Rockauto.com sells a Standard Motor Products Part #EM0517

16180517 (computer) for $85.79 plus the core for your car. I ASS_U_ME that part has been updated. Maybe a call to a dealer or Rockauto would help.

Thanks for your research; Rockauto has a good price too.

I just sent their service department an e-mail; I think I'll call the Caddy dealer tomorrow.

I'll let you know what I find out...

I have found that asking the Cadillac dealer parts guy if you could get a discounted price because you could get it on line at GMPARTSDIRECT for whatever amount and almost always I can get it cheaper at the dealer if you count the shipping costs. Haggle, in a nice way,and you will be surprised how much the price drops.

Very true, I always find that whomever I am dealing with is looking for business and no price is really set in stone. Good idea to always negotiate.

[CaddyChris]

Hey,

I would get the new part # from the dealer and look for that part # somewhere else. I think that's your best route at this point. Call a different dealer as well and see what they say about the price and get the part number from them. I def wouldn't pay the dealer 90$/hr. Who knows how long that will take, 2.5 hours (easily) and there is your new PCM.

[PAUL T]

Hey,

I would get the new part # from the dealer and look for that part # somewhere else. I think that's your best route at this point. Call a different dealer as well and see what they say about the price and get the part number from them. I def wouldn't pay the dealer 90$/hr. Who knows how long that will take, 2.5 hours (easily) and there is your new PCM.

Did you get a quote from gmpartsdirect or cadillac-parts-for-less? They are just dealers that sell on the internet. If it is the ECM, cadillac-parts-for-less listed it for $118.50 with a $90.00 core charge.

[BodybyFisher]

If you can wait, send www.gmotors.com an email and ask them how much. I use them often, Mike

If you go to their site, you can get a quote from them. BECAUSE you have a quicky PCM issue, I would go directly to GM in this instance as they are sure to have updated PCM's.. Good Luck