More on 'check engine' light

[Ralph L. Fullenwider]

HI Steve:

16: Coolant level Sensor Voltage high
31; Engine break output open circuit or short to ground
32; CEL or SEL Short to battery or open circuit
43; Low Coolant
44: Oil or coolant high temp
64: No code
66: Engine knock sensor
68: Idle validation switch open or short to ground
85: Engine over speed

Too many faults reported and this to my mind makes it the input 12 vdc
opening and closing with a spike. The 12vdc is on the DDL plug to the DDEC
on pin H circuit 440. There is a circuit breaker located on the back of the
fire wall, have to trace it out, that supplies the 12vdc and it may be
faulty (known to happen) or you have a bouncing ground with is pin A on the
DDL circuit 150. I am thinking it is the connector corroded to the 12vdc
that is reporting your problem and taking the engine to the default rpm
ergo; 37mph speed. The DDEC may be located at the bottom of the back closet
or on the top of the engine located center top near the back compartment door.

Safe travels,

Ralph and Charolette Fullenwider
84FC35
Ralph's RV Solutions, Duncan, Oklahoma

At 01:25 AM 1/3/2007 +0000, you wrote:
>Thanks for your suggestions. When the problem started I suspected fuel
>quality problems ... been holdin' out for lower diesel price for way
>too long. Fuel drained from Racor revealed chunks of algae ... changed
>both filters, put in Bio-cide, & $614 of diesel. Still get the
>intermittent 'check engine' light on constantly which causes tach to be
>inoperative & speed to be resticted to 37 mph. Next time I switch it on
>the light will function properly & everything works normal.
>
>When the light works correctly & I read the DDEC II codes with
>the 'test engine' switch I get 16, 31, 32, 43, 44, 64, 66, 68, & 85.
>You'd think it was near death ... Cranks up & comes 75 miles without
>missing a stroke. Next morning all fluids are OK, cranks up & comes 100
>miles to home without any problems. Switch it off & back on & 'check
>engine' light stays on.
>
>The pattern when giving problems is: Initial turning on ignition -
> 'stop engine' light does NOT come on momentarily but 'check engine'
>light stays on constantly. Tach doesn't work & speed limited to 37 mph.
>
>re: the question about me being an agronomist ... if I had $$$ I'd hire
>someone to fix the problem instead of trying to steal ideas from
>you "master mechanics". naaaaa ... I'm in the seed cleaning &
>distribution business. A "tinkerer" also ...
>
>Steve & Kathy Enfinger
>Newton, GA
>'91PT40 WBSA
>
>
>