Trouble Code Help

[Guest]

I retrieved the following trouble codes from a 1993 Cadillac Deville. Can you help me decipher?

E 13 - Oxygen sensor not ready (does this mean i have to replace it?)
E 40 - Power steering pressure switch open (????)
E 52 - ECM memory reset indicator (????)
E 53 - Distributor signal interrupt (???? - bad plug wires, coil, ????)
E 85 - Idle throttle angle too high (this seems straight forward enough).

Engine seems to be running a little rough. It will also start choking out after having driven approximately 140 miles in one day. Engine looses power spasmodically. Turning off ignition and letting it sit for a minute or two clears up the problem for a few miles.

edit: oh and i got the interpretation from here: http://www.cadillacforum.com/forum/s...ead.php?t=4543

[tonytheskin]

Check your battery terminals to make sure there is nothing losing a connection and also check where harness plugs to computer. I'll look in my code book to see if it gives any hints/tips.

[Morella]

If I'm not mistaken, a 1993 has OBD1. If you're going to do your own troubleshooting, it might be worth your while to spend $30 on a baud rate box, and get the freeware to use a laptop and monitor the system. I've never found the codes to be particularly useful, whereas I have found a spreadsheet full of continuously updated diagnostic data to be extremely useful.

-d

[Guest]

Those sound like good suggestions. I cleared out the codes in case they were older or false codes. i let the engine idle for a while and so far the only thing that came back was the throttle idle angle too high code. i'll drive it around and pull the codes once it starts sputtering again.

in my 85 shop manual it says i'm supposed to be able to enter engine diagnostic mode, which will give me all kinds of detailed data on engine performance and settings. i haven't figured out how to get there in the 93, though.

[Morella]

Or you could do the old-fashioned thing and just take a look at your spark plugs.

-d

[Guest]

i finished replacing all the plugs and wires today. it does seem to run a bit smoother. don't know if that's the problem, though.

i'm thinking about pulling the oxygen sensor off to see if it's gunked up.

edit: i think it was the original plugs and wires. the plugs had some whitish build-up on them. some of the wires were extremely hard to disconnect

[Guest]

ok, so according to some research i have done, a problem with the throttle position sensor can cause the issues i'm seeing.

i will try to perform the functional test tomorrow after work. It's supposed to put out a certain range of voltage, which i should be able to test with my multi-meter.

seems like this could be a good bet since the symptoms match, and the trouble code i'm getting also points to the TPS.

[Scary Guy]

... reports?

[Highbars]

ok, so according to some research i have done, a problem with the throttle position sensor can cause the issues i'm seeing.

i will try to perform the functional test tomorrow after work. It's supposed to put out a certain range of voltage, which i should be able to test with my multi-meter.

seems like this could be a good bet since the symptoms match, and the trouble code i'm getting also points to the TPS.

Your multi-meter should have a min-max feature so as you run the range of the sensor and watch the meter it might not register the fault on the screen but the min-max will be recorded. Checking for proper adjustment of sensor and clean the throttle plate and intake bore with sensor safe carb cleaner to remove any build up of crud that might restrict air flow at idle. After cleaning let engine idle for 5 - 10 minutes allowing the IAC (idle air control) motor to relearn air flow.

[Guest]

ok well i tested the throttle position sensor, and it seems to work as expected. However i did find and replace another dry-rotted vacuum hose. we shall see.

[Morella]

And just exactly how much time did you spend on those TPS reports?