Question about 1994 Pontiac Bonneville

3 Answers

OBD 1 and 2 will not communicate with PCM.

I have a '94 Pontiac Bonneville SE. The car starts and will sometimes idle (rough) and stall, Idle OK but after fluctuating throttle will maintain a high idle (About 3000 RPM manifolds go Cherry). All occur while in Open Loop. Closed Loop, sometimes will drive fine and then intermittently stall at idle and or stall continuosly closed throttle/ at idle.
The car is a OBD 2 phase in. OBD connector is "wedge side" (OBD 2) but the emmission label does not designate this vehicle as OBD 2. OBD 1 and 2 interface will not communicate with PCM. Check engine lamp will illuminate in Closed Loop.
How can codes be accessed? Is PCM OBD inoperative? I have '93 Bonneville GM Shop manuals. Are systems similar enough to use OBD fuction diagnosis by referencing wire color @ OBD connector?
GM should have left good enough alone and stuck with engine light code display!

Posted by on

  • 2 more comments 
  • m_hanks66 Nov 13, 2008

    What old system? I purchased my first interface tool in 1984, called a Monitor 84. This was no different from the current interface scanner I used, an Innova OBDI/II new model. After investigating the capabilities further, this OBD tool does not have the capability to work on this model/year.

    You did not understand my comment. Since the inception of onboard diagnostics/GM's CCC system and up until '93 model year you were able to extract the ECM (PCM) and BCM codes with only the paperclip. A high impedance multimeter, test light, jumper wires and a GM shop manual are all that were (are) necessary to diagnose and repair emission/body control systems. The shop manuals symptom, trouble shooting and diagnostic charts/tables are, and will always be, intended to be a Techs main tool. The information/functions an on board computer provides/controls has basically not changed. The emission controls/sensors/methods have. My point is, rather than extracting codes simply and economically, this change to the OBD tool interface requirement requires one to borrow or purchase the Tool to accomplish this simple task. The interface tools are simply convienient and allow real time reading and contol activation capabilities. The Cadillac, Toronado, Riviera O.B.D. systems that allow interface via the climate control systems was a "good" idea. No "special" tools required there and have/had all the capabilities of any of the available interface monitors.

    So, sorry not wrong. As I stated earlier, the cars system is not designated OBDII because this would be exhibited on the emissions label. The interface connector is non OBD I because it is not rectangular but has angled sides like OBD II. It falls in an interface period between I and II, unfortunately.

    I thought maybe someone else may have ran into a similar issue. I did confirm the fuses/power supplied in the diagnostic system is OK. Maybe the PCM is blown? I guess my best bet will be to get access to this model years service manual.

    Thanks for your help. Any other ideas would be welcome.

  • yadayada
    yadayada May 11, 2010

    I have no idea what you talking about, OBD 1 started in late 83, very poor system, very little self diagnostics like OBD 2

  • yadayada
    yadayada May 11, 2010

    You are wrong, the OBD 2 system is far superior in every way to the old system, no you can't access it by using the CEL but the scanner does a much better job. Are you sure this is OBD 2?

  • Anonymous Mar 31, 2014

    OBD code P0410

×

3 Answers

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

I have the exact same problem with my 94. I would like to know what you did to fix it. Please help.

Posted on Mar 20, 2013

  • Level 1:

    An expert who has achieved level 1.

    Corporal:

    An expert that has over 10 points.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 15 Answers

You are describing exactly what a lot of 94-95 GM car owner are feeling. I have an AUtoXray6000 scanner and it can read the trouble codes on this car, (I have a 95 Bonneville) but wont read the data stream. Basically you have a OBDII plug, but the car is controlled by the same OBDI system as others prior to 96. There are some scanners that have the ability to read the codes and data stream on these cars, others can only read the codes. If you can get or design an interface cable plug and know how to route the wires, you're in like flynt. Here is a web site that makes parts for a conversion cable.. http://www.obd2allinone.com/sc/pages.asp?pageid=63

Posted on Feb 06, 2009

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that got 5 achievements.

    Governor:

    An expert whose answer got voted for 20 times.

    New Friend:

    An expert that has 1 follower.

  • Expert
  • 160 Answers

A blown fuse will also cause the obd to not communicate

Posted on Nov 12, 2008

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Computer or fuel pump


check the Idle Air Control

Jun 26, 2013 | 1995 Pontiac Bonneville

1 Answer

94 nissan altima won't start and iddle after cleaning IACV valve


An IAC (idle air control) motor is designed to adjust the engine idle RPM speed by opening and closing an air bypass passage inside the throttle body. The cars computer or PCM (powertrain control module) receives information from various sensors and will output signals to adjust the idle air control motor in or out to adjust engine idle speed by controlling engine idle air. An idle air control motor can fail one of two ways, either the motor short circuits and stops working or the motor will develop high resistance and cause the idle air control motor to react slowly, either failure can cause the engine to stall at idle. When a trouble code scan is performed it sometimes won't always detect a failed or weak idle air control motor.

Oct 08, 2012 | Nissan Altima Cars & Trucks

1 Answer

Engine missing at idle.....sometimes will stall. and sometime its hard to start..will crank for a while before its starts


Start with new spark plugs, wires and distributor cap. If it wasn't for the missing at idle comment, the hard starting is usually caused by a fuel pump going bad. Don't know if yours is electric or not, but either type will have that symptom.

So start with the easiest.

Dec 26, 2010 | 1992 Pontiac Bonneville

1 Answer

98- bonneville started to warm up ran for few minutes then died. waited about 1/2 then started again drove around block parked in drive let idle died again. also when it rains car idles rough .


check and or change the plug wires also check for a crack coil pack which is highly likely on that model and also check the ignition module as well

Jan 22, 2010 | 1998 Pontiac Bonneville

1 Answer

Car Dies on Idle


Mechanic replaced the MAS. Car still idles a little rough and battery needle gage still fluctuates.

Sep 18, 2009 | 2000 Pontiac Bonneville

1 Answer

1991 Pontiac Sunbird SE sometimes stall after starting


2 possable... bad fuel injector....or leaky intake gasket worst case the intake manafold is craced

Jul 17, 2009 | 1991 Pontiac Sunbird

1 Answer

1995 pontiac bonneville stalls


I just went through lots of troubleshooting and expense on my 1996. Whenever I would lift my foot off the accelerator and was below about 30 mph, the rpm's would starts jumping around and sometimes it would stall. If I gave it a little gas (accelerator), I could sometimes keep it running. It also backfired once in a while. Starts right back up. Also, if I let it idle while in part, it would die after 1-2 minutes.

I ended up finding a hole in the fuel regulator. About a ~$70 part if you get an AC Delco, but very simple to change.

Nov 27, 2008 | 1995 Pontiac Bonneville

1 Answer

Rough idle stalls at low rpm's


hello first check your idle with the car running foot on brake see were your rpm reading is if your below 500rpm check your label underhood for your curb idle setting second see if theres a adjustment screw you can increase were your gas cable lever rest against your set screw underhood if you feel confident enough remove your iac motor idle air control valve if the bore were the end of the pintle extracts out to close has varnish builup our carbon it will stick creating vacuum leak type senario causing stalling rough idle sometimes even no start conditions good luck

Sep 14, 2008 | 1988 Honda Accord 4 Door

Not finding what you are looking for?
1994 Pontiac Bonneville Logo

2,645 people viewed this question

Ask a Question

Usually answered in minutes!

Top Pontiac Experts

yadayada
yadayada

Level 3 Expert

70365 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22041 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

6878 Answers

Are you a Pontiac Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...