Well I guess I'm officially a member of the notorious Service ASR light club.lol
Here's my issue. Service ASR light was coming on and off intermittently, It was usually upon startup. When the light was on the car would shift rough(automatic), light off she was all good. I drove back from Florida the other day about 700 miles. I go to start her up and attempt to drive her to the store yesterday(she is my daily driver) ASR is on, she's bogging sputters and just about wants to stall out. Service Engine is on, upon pulling codes O2 sensor needs to be replaced I have sensor just waiting for a good day(no garage). Any ideas?? Could it be ECM related??? What I have replaced, Alternator, belt, all the sensors except crank/cam sensor. New battery, I had rebuilt tranny done about 1.5 years ago. Intake gaskets I did. I did clean out all the crud that was im the wiring harness that goes from under the car that goes from ASR box all along the rocker. (I could have made a sand castle) I also updated my headlights to LED with a converter to avoid the flickering issue or any overloads. Now the ASR is on all the time. Any help or insight would be awesome.

I appreciate it.

Thanks

 

When my 93 did this, it was always related the TPS switch bad, or loose wiring at the plug for it.

 

My 94 also has the same light. However it has no impact on any operations. Soon once I get my exhaust back together ima plug my mt2500 in and see what it says.

 

When ASR light comes on the problem usually starts were the Rubber hits the Rd, Check the sensors you might have an intermittent drop out or a dead one a shakey wheel bearing also can contribute to throwing a light
Before you say I'm confusing the ABS with ASR how else would the system know that the rears are breaking free

 

Hi all ok I was asked to pull codes and check back in. So here is what I got.
1.0 CCM No codes
4.0 ECM/PCM C34(MAP sensor circuit low-high vacuum out of range or MAF sensor circuit)
H43
H34(I did replace both MAP and MAF) it's back again
H22
9.0 ABS H64
A (air bags) nothing
Upon reading the service manual(it's not the greatest one, it does the job most of the time) I did test the the Terminals for both MAP and MAF with my volt meter. I just didn't get to back prob(weather) this is what I got. All readings were taken with the key in the on position but not started
MAP Sensor
Terminal A-Ground .62v
Terminal B-Signal Wire .2v
Terminal C SV Ref .2v

MAF Sensor
Terminal A-Signal Wire 5.03v
Terminal B-Ground 0v
Terminal C-Power 12v.
That's all I have right now.
Both the MAP, MAF were replaced. In my opinion I'm thinking faulty PCM. Hit me with your knowledge. I'm just a girl who enjoys working on my cars.
Thanks everyone

 

Clean and verify TPS is good. That little sensor at the throttle will cause ABS errors.
Low/High vacuum, check the rubber gasket under the MAP.
Check Battery voltage while running under load too. Basic, I know, but I am not there. I had a extender stud on negative terminal, caused all kinds of electrical problems due to being nonconductive some of the time.
Check the grounds under throttle body on block above water pump. That wire is important.
In my opinion, the 94 ECM/PCMs never had many issues, the 92/93 did.
I am thinking it is a grounding issue. Too many faults.
ALso, in my 93, I always get codes in CCM/ECM/ABS. I clear them, and they come back. No dash lights, all components work

 

I believe that the MAP reference should be 5VDC and you are getting only 0.2 VDC. That 5VDC comes from the PCM but before you blame the PCM look at other sensors that share that 5VDC reference voltage. You may find a sensor shorting out the 5VDC.
I had this on my 96 and it turned out to be a shorted AC pressure sensor switch. The shop manual had me pointing in the direction of the ASR module in the back of the driver's seat instead.
Leave a digital meter on the Ref. 0.2VDC of the MAP sensor. Meanwhile one at a time with ignition On engine not running disconnect sensors that use that Ref 5VDC. If you see the Ref voltage come back up to 5VDC then you found your bad sensor.
Also look for any shorted wiring too. You can/should be able to follow the Ref wire from the PCM and remove that wire at the PCM main connector. And then try to measure the Ref voltage right at the PCM.
Good luck!

 

Ok. There is No Voltaqe at Terminal C at the MAP Sensor. This a Current problem indicated by the C34. (C's always set their corresponding H code.). Fix This First.
The gray wire must be 5 Volt with the key in RUN. Broken wire? The connector pigtail may have been replaced in the past, and there is a jankey splice in the harness? Peel the harness covering off and check the wires for a few inches back from the MAP connector.

This wire begins at B29 at the PCM. It also branches to the A/C pressure transducer that is on the smaller A/C metal line just forward of the A/C "suitcase". Also a gray wire, should be 5 Volts . (I suspect that it will be 5V, and ok, because you don't have codes for the transducer.)

You have to figure out why you don't have 5V on the gray wire at the MAP sensor. If you have 5V at the A/C transducer, which I think you do, its wiring or connections at the MAP.

EDIT/ADD: Pay attention to grandsport's post regarding the A/C transducer pulling the gray wire 5V circuit low. Put your meter on the MAP's gray wire, key in RUN and disconnect the A/C transducer. If the voltage at the MAP recovers to 5V, it is a shorted transducer, same as he had. (Doesn't explain no transducer codes, however.). This is a great observation by grandsport.

EDIT/ADD II: The MAP's 5V reference voltage circuit is also shared with the TPS. There is likely a correlation between these MAP, TPS, and ASR codes being caused by the reference voltage being pulled low.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~

• I don't see any codes associated with MAF. Ignore MAF for now.
• H43 is a Knock Sensor code. Again, won't cause driveability problems. Knock Sensor codes can be caused by poor connection where they screw into the block, bad electrical connection, or sometimes a faulty sensor.
• 4:H22 and 9:H64 are both associated with the TPS sensor. These will set if you disconnect the TPS with the key in RUN. You've addressed the TPS,

Fix the 5V problem at the MAP.
Then clear all the codes, and see if / which come back.

To clear codes:
(Module 'point' 7 is the clear codes display for that module.)
Set up your jumper between 4 and 12.
Turn key to RUN.
Push TRIP RESET until the desired Module displayed.
Press TRIP/ODO until " x.7" (Ie for PCM, you want 4.7) is displayed.
Press and HOLD ENG/MET button until "- - -" is displayed.
Repeat for other modules as required.

Fix the 5V at the MAP.
Clear all the modules.

Report back.

 

Check complete circuit on sensors, to ground.

 

I am in the process of getting all this done today.
Will give an update later this evening
Thanks to everyone

 

Just a quick Thank You to all the help and suggestions from everyone it is much appreciated. I'm still in the learning process and appreciate everyone's support.
Thank You Again.

 

I've had mine come on at the drag strip because it was a little low on brake fluid... and another time it came on and I pulled the codes on the dash and it was a TPS sensor PN 10177912 C40818. If I remember correctly the part is located on the passenger front wheel well near the windshield washer fluid tank.

 

I think that pic is incorrect, or the name of it is. The TPS sensor is on the passenger side of the throttle body.

 

That pic is of the Throttle Position Sensor BUFFER. The signal from the TPS is routed to the buffer, split, and sent to the PCM (engine/trans) and the ABS/ASR.

Girlztoy's car has the buffer. It is located on the outboard side of the HVAC blower case on the RH side of the car. Just aft of the washer fluid filler.

In her opening post, she indicated that the ASR light was coming on at start-up, and that the transmission "shifted hard". Loss of TPS (C22) will cause a default to transmission Max Line Pressure, and it will shift hard. While the present TPS codes are History, there was something affecting TPS.It could be the buffer but she needs to fix the MAP voltage first, and go from there.

She needs to address the MAP 5V reference voltage first. C34 (MAP) is the only Current Code. After that is resolved, she can clear the codes and see which ones come back. What ever is causing the MAP reference voltage maladies may also be affecting the TPS.

 

As I said, it was not the TPS sensor.
Never, since 1996 have I ever heard of the buffer, or the TPS buffer failing. Not saying it cant. Just my 2 cents.

 

You are correct the 96 does not have the TPS buffer.

 

Sorry, I meant since 1996, when I first had a C4. But thanks for educating me, never to humble to learn.

 

No, I misinterpreted your post not your fault.

 

Good Afternoon everyone, i wasnt feeling very well the past couple days and it was a little chilly outside killed my arthritis. Any how upon looking at the wires from the MAP they all looked good, but definately need new electrical tape and loom. Just crumbled apart. I did notice that the pigtail is broke. The plastic being broke the connector would not stay in properly. I am going to check the rest of the pigtails and wiring order up what I need, she is due for an oil change and a coolant flush. I will do all that as well. For now i will post an update after installing new pigtails, rechecking the voltage clear the codes and recheck again. TPS is new I replaced yhat a few months ago or so.(i reused the orange looking thing, it didnt come with a new one). The MAP is new I replaced that myself. (I do keep the old parts,You never know). It will be a few days or so until i can get everything.(SSDI Sucks). I will also post some pics of my baby.

will report back soon

aThanks Everyone