swifty Posted March 22, 2010 Report Share Posted March 22, 2010 hey guys i tried to check codes today and i got a 7 coolant sensor, i have change the coolant sensor and sender, both on the intake, my question is which one sets this code and what do you do to remove the code? or does it clear one the problem is fixed. has anyone else had this problem Link to comment Share on other sites More sharing options...
JAinsworth Posted March 22, 2010 Report Share Posted March 22, 2010 Did you disconnect the battery to reset the codes? Link to comment Share on other sites More sharing options...
swifty Posted March 22, 2010 Author Report Share Posted March 22, 2010 no i didnt but being its an old system i thought once it seen it was fixed it would atomaticly clear once it passed, how do you check the codes, to make sure im even doing it right Link to comment Share on other sites More sharing options...
Indiana Posted March 22, 2010 Report Share Posted March 22, 2010 How did you get that code to begin with? Did you test the sensors or just change them? Maybe they were good. What sensors did you get? The CTS has a molded oval end and the harness plug used to be a boot but its likely mostly broken off now and the temp. gauge unit for your temp. gauge had the usual molded plastic plug. Link to comment Share on other sites More sharing options...
swifty Posted March 22, 2010 Author Report Share Posted March 22, 2010 with the connector in the glove box Link to comment Share on other sites More sharing options...
mikec Posted March 23, 2010 Report Share Posted March 23, 2010 StarQuest ECUs do not reset error codes 2 and higher. You must disconnect the battery for 5+ seconds to clear the codes. Code #7 is the temp sensor dedicated to the ECU (not the sensor for the dash temp gauge). This is the 2-prong sensor in the intake manifold near the injection mixer assembly and the bolt that supports the oil dipstick. The connector tangs point straight up on this sensor. The dash temp sensor is the one near the thermostat... it points sideways. Totally different part number too. The ECU sets code #7 whenever the sensor resistance leads to output voltages above 4.5volts or below 0.1 volts. The ECU supplies a 5.0 volt signal to one side of the sensor, the other side of the sensor goes to a resistor and then to ground... i.e. this variable-resistance sensor and the ECU's resistor form a voltage divider. When the output voltage is "outside" the range of possible engine temps you get the ECU error code. It can be caused by* bad sensor obviously* dirty/corroded contacts on the harness connector especially if the squarish rubber boot has disintegrated* wires to/from the ECU have busted* corroded connections at the ECU terminals. This happens on the 87-earlier cars if the windshield leaks: water goes into the roof structure and flows down the bodywork "A" pillar (the posts on either side of the windshield) and gets dumped onto the top of the ECU. The 88-later cars flipped the ECU over so the connectors don't get rained on. The sensor should read 300 ohms or lower on a fully warmed up engine, and 2000 to 5000 ohms on a stone-cold engine. With the engine stone cold and shut off, unplug the electrical connector of the sensor. Hook an ohmmeter to the sensor directly; leave the harness connector unplugged. Verify the resistance is in the several thousand ohm ballpark. Start the engine and let it warm up while you keep a constant eye on the ohmmeter. Verify the resistance smoothly decreases as the engine warms up. If the resistance "hiccups" or drops/rises at any point the sensor is junk. mike c. Link to comment Share on other sites More sharing options...
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