RE: Closed loop/Open Loop

["Bill Collins" <photo@intrex.net>]

On CIS systems, the transition from open loop to closed loop is controlled (at least partially) by a coolant temp. switch, usually located near the head, on the big coolant hose.  I think the ECU has some say in the matter too, but if the switch is jumpered, the system always runs open loop.

Bill

---------- Original Message ----------------------------------
From: "Aaron Ness" <aaron@makuta.com>
Reply-To: <aaron@makuta.com>
Date: Tue, 10 Oct 2000 23:29:44 -0500

>AFAIK, any car with an O2 sensor operates in an open loop mode until the O2
>sensor comes up to temperature.  As soon as it's hot enough to work, it
>gives feedback to the engine management system, whatever that may be, and
>then you have closed loop operation.
>
>Open loop simply means there is a set routine, but there is no feedback from
>sensors, etc., that can modify that routine.  IOW, if it's running rich, it
>can't take input from the O2 sensor and lean things out.  OTOH, a closed
>loop system uses such feedback and is capable of making adjustments to
>compensate for changes in operating conditions.
>
>Someone correct me if the blanket statement above is wrong.
>
>Aaron
>'82 Scirocco
>'84 Scirocco
>'70 Bug - Hibernating
>'87 Jeep Cherokee 4.0
>
>
>> -----Original Message-----
>> From: owner-scirocco-l@scirocco.org
>> [mailto:owner-scirocco-l@scirocco.org]On Behalf Of Christopher Michael
>> Boggs
>> Sent: Tuesday, October 10, 2000 9:42 PM
>> To: scirocco-l@scirocco.org
>> Subject: Closed loop/Open Loop
>>
>>
>> could someone please help me with this.  When your car first
>> starts in the
>> morning it is running closed loop? correct?  I seem to get
>> closed loop and
>> open loop mixed up.  Also dose anyone know how long a rocco
>> runs closed
>> loop before switching over to open loop?
>>
>>
>> Chris
>>
>>
>> --
>> Email LIST problems to: scirocco-l-probs@scirocco.org. To
>> unsubscibe send
>> "unsubscribe scirocco-l" in the message to majordomo@scirocco.org
>>
>
>
>--
>Email LIST problems to: scirocco-l-probs@scirocco.org. To unsubscibe send
>"unsubscribe scirocco-l" in the message to majordomo@scirocco.org
>
>

--
Email LIST problems to: scirocco-l-probs@scirocco.org. To unsubscibe send
"unsubscribe scirocco-l" in the message to majordomo@scirocco.org