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15yearsaturnguy
15yearsaturnguy, Saturn master tech
Category: Saturn
Satisfied Customers: 1918
Experience:  25 years automotive experience, 15 years with Saturn
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1999 Saturn: idle speed..radiator cooling fan..warning lights

Customer Question

1999 Saturn SL2, 1.9L Twin Cam Started to have eratic idle speed and radiator cooling fan stopped working. No dash warning lights or stored codes. Changed the engine coolant temperature sensor - did not help. Wiggled the wires to the pcm and the fan started working. Cleaned the throttle body and idle air control valve. Did not help. Am not getting a variable voltage from the pcm to the idle control valve - get a constant 10.99V reading.
Submitted: 6 years ago.
Category: Saturn
Expert:  15yearsaturnguy replied 6 years ago.

15yearsaturnguy :

Do you have a drivability issue off idle?

15yearsaturnguy :

Is it misfiring or just a rough idle?

15yearsaturnguy :

The top engine mount gets collapsed on these and causes a hell of a bad idle from the engine grounding out below.

15yearsaturnguy :

Try jacking the engine up with a floor jack and see if it improves.

15yearsaturnguy :

The wires are not usually an isue at the pcm, but if you wiggled them and the fan started working, you may have a connection issue there.

15yearsaturnguy :

Look at the cts connector first, then look at a possible top engine mount collapsed

15yearsaturnguy :

If still no solution, try getting some scan tool data.

15yearsaturnguy :

Look for fuel trim, iac counts

15yearsaturnguy :

cts temp, iat temp,

15yearsaturnguy :

things like that.

15yearsaturnguy :

let me know how I can help

15yearsaturnguy and other Saturn Specialists are ready to help you
Expert:  15yearsaturnguy replied 6 years ago.
let me know if I can help
Customer: replied 6 years ago.
Did the tests you recommended. No Help. The fact I wasn't getting a variable voltage to the idle air control valve kept sticking in my mind. I pulled all the harness connectors out of the pcm to recheck for corrosion. Everything looked squeaky clean. After pulging the harness connectors back into the pcm, everything worked normally. There must have been a slight amount of surface corrosion on the pins and connectors. I really appreciate you time and help. I will accept the answer so you can get paid. This is a great website and will use it and recommend it highly in the future. Thanks again!
Expert:  15yearsaturnguy replied 6 years ago.

ok. Thanks