: 1989 Brougham check engine light?



cadillacdeville
09-28-06, 11:01 PM
I just recently purchased a 1989 cadillac Brougham with 70k origonal miles and changed the plugs and wires and the check engine light has come on I thought that maby it had to adjust to the new plugs but I drove it a little more than 5mi and its still on I'm more used to the older cads with out the ECU so any help would be much appreciated :thumbsup:

joe_padavano
09-29-06, 09:27 AM
With the key in the RUN position, but the engine not started, you can short the two upper RH terminals in the diagnostic connector under the steering column. This will put the computer in the diagnostic mode and allow the CHECK ENGINE light to flash in a sort of morse code. The codes are all two digit and each is repeated three times. The first thing it will flash is Code 12, which just means the system is working. You'll see the light flash as follows:

ON - Long OFF - ON - OFF - ON - Long OFF

This will repeat three times, followed by the next stored code. As an example, a Code 24 would be represented as:

ON - OFF - ON - Long OFF - ON - OFF - ON - OFF - ON - OFF - ON - Long OFF

After all stored codes are displayed, the cycle repeats with a Code 12.

Knowing the stored code, you can then figure out what the computer is trying to tell you.

cadillacdeville
09-30-06, 01:19 AM
The only connector I could find wasn't under the column but down below the glove box and nothing would happen when I used a jumper wire between any of the terminals.

cadillacdeville
10-03-06, 10:31 PM
well the first problem was resolved the fuse for the ECU came out and caused the light to stay on but I have also just replaced the O2 sensor and rebuilt the carb and installed a TPS switch and have got the on board diagnostics working now the light comes after I start the car stays on for a few minutes will I drive around then goes out but comes right back on after you restart the car I checked the ECU and it gives this signal but I dont know how to read it it goes FLASH FLASH FLASH PAUSE FLASH then repeats 2 more times and then back to code 12 could some one please tell me what code this is and how to read the codes?

cadillacdeville
10-05-06, 12:08 AM
Is on-off-on-off-on-off-------then on again a code 31 if so what does it mean any help is much appreciated.

90Brougham350
10-05-06, 10:09 AM
Someone will have to verify this, but I think 31 is a shorted MAP sensor.

kdrolt
10-05-06, 03:31 PM
TroubleCodes.net- engine & OBD2 Trouble Codes and Technical info & Tool Store. (http://www.troublecodes.net/GM/)

Not sure what the engine size is on an 89 Brougham; check the VIN for the 8th digit, then use the above link. HTH.

3141592654
07-03-07, 09:19 AM
1.) Take the top of the dashboard off (Brougham models).
2.) Find the "Check Engine" light bulb.
3.) Remove it.
4.) Smash it under foot.
5.) Replace the top dashboard.
6.) No more check engine light problems.
7.) Enjoy your Caddy!

joe_padavano
07-03-07, 10:25 AM
1.) Take the top of the dashboard off (Brougham models).
2.) Find the "Check Engine" light bulb.
3.) Remove it.
4.) Smash it under foot.
5.) Replace the top dashboard.
6.) No more check engine light problems.
7.) Enjoy your Caddy!

Right, because ignorance is bliss - until the car finally dies on the highway someplace...

RocketFast321
07-03-07, 05:13 PM
http://autorepair.about.com/library/ts/obd-i/bl-dtcs-55.htm?once=true&
31 Canister Purge Solenoid Circuit

But when i look on another site their is no code 31.

Try using the Climate Control to pull codes

http://www.troublecodes.net/cadillac/cadbrom.shtml

3141592654
07-04-07, 09:01 AM
Right, because ignorance is bliss - until the car finally dies on the highway someplace...

Need real gages put into the Caddy...not just one big red light that lights up when all the moons of Venus align right. You can tell a mountain of information with just oil pressure, coolant temperature, and charge current.

Really, how many people drive around for months with the "Check Engine" light glowing brightly?

pi-

joe_padavano
07-05-07, 09:31 AM
Need real gages put into the Caddy...not just one big red light that lights up when all the moons of Venus align right. You can tell a mountain of information with just oil pressure, coolant temperature, and charge current.

All good, but none of these will tell you the error codes stored in the computer - or the fact that there even IS an error code stored.


Really, how many people drive around for months with the "Check Engine" light glowing brightly?

pi-

People are stupid. What else do you want me to say?

The Ape Man
07-08-07, 08:04 AM
Off and warmer trick does not work on 307 cars. Riding around with the engine lamp on is a good way to land up on the back of a hook. It would be different if the problem were known and was something that could let the car fly without going into open loop.

The Ape Man
07-08-07, 08:11 AM
Try pulling the plug offa da canister purge solenoid. Little black 2 litre sized plastic container where a second battery should live. Has a bunch of small and large vacuum lines connected at right angles on top. IIRC the plug might even be red in color. Those solenoids used to short. They can blow up a good ECM so try it out right away and see if your lamp goes away. Leave the thing unplugged and just forget about it if the lamp goes out.

joe_padavano
07-09-07, 01:22 PM
Try pulling the plug offa da canister purge solenoid. Little black 2 litre sized plastic container where a second battery should live. Has a bunch of small and large vacuum lines connected at right angles on top. IIRC the plug might even be red in color. Those solenoids used to short. They can blow up a good ECM so try it out right away and see if your lamp goes away. Leave the thing unplugged and just forget about it if the lamp goes out.

Rather than randomly disconnecting stuff, why not read the stored codes and make an intelligent diagnosis? Jumper the two top RH terminals of the ALDL connector together and the check engine light will flash with the trouble codes (assuming you haven't removed the bulb as others have suggested).

The Ape Man
07-09-07, 06:42 PM
Rather than randomly disconnecting stuff, why not read the stored codes and make an intelligent diagnosis? Jumper the two top RH terminals of the ALDL connector together and the check engine light will flash with the trouble codes (assuming you haven't removed the bulb as others have suggested).

Who's doing anything randomly? Re-read the thread. He got a code 31. Canistor purge valves shorting was a known issue in that era.

joe_padavano
07-09-07, 07:37 PM
Who's doing anything randomly? Re-read the thread. He got a code 31. Canistor purge valves shorting was a known issue in that era.


DOH! I missed that. Sorry.

ReagansRollsRoyce
07-10-07, 07:53 PM
Not positive on a 31 meaning but... as for the flashes

On my '87 It always flashes code 12 first three times to show the system is working...flash *pause* flash-flash...repeat 2 more times

a 31 would come out like so flash-flash-flash *pause* flash....this would repeat 2 more times and as long as there were no other codes it would then do 12 again.

when it's a higher number than one, the flashes are going to be really close together...so the pause shows you where the first digit stops and the second begins

ReagansRollsRoyce
07-10-07, 07:58 PM
Off and warmer trick does not work on 307 cars. Riding around with the engine lamp on is a good way to land up on the back of a hook. It would be different if the problem were known and was something that could let the car fly without going into open loop.

^

Yeah...my old mechanic taught me to use a paper clip to read them out of the data port under the ashtray. the two top right holes.