Codes. Should I worry about 'em?

[OL' WHITEY]

My '93 has ALWAYS flashed an intermittent check engine light. I bought the car from a friend who bought it new. He had the same problem from the time the car rolled 3,000 miles. Back then, the dealer could find no problem. It used to only do it once or twice once I got a mile or two down the road first thing in the morning. It has gotten worse lately. Now I get the flashing light pretty much any time I accelerate...even slight acceleration. The car runs great. I have a custom chip, but it has been in a year or so. I'm sure the chip is the reason for a couple of these codes, but can't be the reason for the more frequent blinky light. I guess what I'm saying is that I didn't tamper with anything lately that may have caused the light to start blinking more frequently. Maybe it's the colder weather? Anyway, here's the codes:

KOEO: 15 pcrom fault
67 clutch switch circuit
96 fp circuit open battery to eca

KOER: 12 ecm can't control idle during high speed
67
69

Should any of these codes worry me? Any ideas on the blinking check engine light? Lemme' know. Thanks!

 

[DTT92LX]

My blinking CE light was bad o2s. Replaced 'em and no more light...

 

[jrichker]

Code 15 - No Keep Alive Memory power to PCM pin 1 or bad PCM (Memory Test Failure). The voltage to the Keep Alive Memory (KAM) is missing (wiring problem) or the KAM is bad. The KAM holds all of the settings that the computer "learns" as it operates and all the stored error codes that are generated as a result of something malfunctioning while the engine is running. Use a voltmeter to check the voltage to the pin 1 on the computer - you should always have 12 volts. No constant 12 volts = bad wiring. If you do always have the 12 volts, then the KAM is bad and the computer is faulty.

Wiring diagrams for the proper model years are next…

For 86 models see http://www.autozone.com/images/cds/gif/large/0900823d80167158.gif

For 87 models see http://www.autozone.com/images/cds/gif/large/0900823d8016715e.gif

For 88 models see http://www.autozone.com/images/cds/gif/large/0900823d80167162.gif

For 89-90 models see http://www.autozone.com/images/cds/gif/large/0900823d8019595f.gif

For 91-93 models see http://www.autozone.com/images/cds/gif/large/0900823d80195960.gif


Code 67 - clutch not depressed (5 speed) or car not in neutral or park (auto) or A/C in On position when codes where dumped. Possible neutral safety switch or wiring problem. You can generally ignore this code, since it has no effect on engine performance.

Code 96 – KOEO- Fuel pump monitor circuit shows no power - Fuel pump relay or battery power feed was open - Power / Fuel Pump Circuits.

Look for a failing fuel pump relay, bad connections or broken wiring. The fuel pump relay is located under the Mass Air Meter on Fox bodied stangs built after 91. On earlier model cars is under the passenger seat. On Mass Air Conversions, the signal lead that tells the computer that the fuel pump has power may not have been wired correctly. See http://www.stangnet.com/tech/maf/massairconversion.html

To help troubleshoot the 96 code , follow this link for a wiring diagram for 87-90 models http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif for 91-93 models see http://www.autozone.com/images/cds/gif/large/0900823d80195960.gif

Look for power at the fuel pump - the fuel pump has a connector at the rear of the car with a pink/black wire and a black wire that goes to the fuel pump. The pink/black wire should be hot when the test connector is jumpered to the test position. . To trick the fuel pump into running, find the ECC test connector and jump the connector in the lower RH corner to ground. http://www.mustangworks.com/articles/electronics/eec-iv_codes.html for a description of the test connector. it. No voltage when jumpered, check the fuel pump relay and fuse links.

Using the diagram, check the red/black wire from the fuel pump relay: you should see 12 volts or so. If not, check the inertia switch: on a hatch it is on the drivers side by the taillight. Look for a black rubber plug that pops out: if you don't find it, then loosen up the plastic trim. Check for voltage on both sides of the switch. If there is voltage on both sides, then check the Pink/black wire on the fuel pump relay: it is the power feed to the fuel pump. Good voltage there, then the fuel pump is the likely culprit since it is getting power. No voltage there, check the Orange/Lt blue wire, it is the power feed to the fuel pump relay & has a fuse link in it. Good voltage there & at the Pink/black wire, swap the relay.

Code 12 -Idle Air Bypass motor not controlling idle properly (generally idle too low) - IAB dirty or not working. Take it off and clean it thoroughly with throttle body cleaner. Clean the electrical contacts at the same time.

According to http://www.troublecodes.net/Ford/ there is no valid code 69 for T5 equipped cars. The code 69 is for 94 & later AODE cars

 

[OL' WHITEY]

Thanks for all the good info. I replaced O2 sensors last night and cleaned the EGR valve. I'm not getting the blinky CE light anymore. Jrichker, I'll take your suggestions and check out that fuel pump relay code, and the idle air bypass code. Thanks again, everybody!!