Knock Knock... Whose there?
#11
The KS module in your car is a small circuit board plugged into the PCM, unscrew the small door on the PCm to get to it. If the wiring is good you may want to swap the KS module with a good one before buying a new one. If you need a new one, get one for the LT4 Corvette, much less false knock & better power.
#13
Key ON
1) With the BLU wire disconnected from KS probe back towards the PCM
you should see 5 volts coming from the PCM.
0 Volt = open or grounded wire shorted to ground, or bad KS Module or PCM
2) Measure resitance from KS terminal to ground, should be 3300 to 4500 OHM.
If out of range the KS not properly seated or bad KS. (The KS has to make good electrical contact with the engine block, no sealant on threads, and has to be torqued to spec.
Key OFF
3) Disconnect the "D" connector from PCM, look back on pin #22 towards KS, should be ) 0 Volt, if not the wire is shorted to battey.
4) Reconnect all wires
Key ON
Backprobe at one end of the BLU wire should get 1.5 Volt. (The KS normally forces thr 5 Volts from the PCM down to 2.5 Volt.
During normal operation the KS sends an AC voltage to the KS module, the voltage depends on the loudness of the knock.
1) With the BLU wire disconnected from KS probe back towards the PCM
you should see 5 volts coming from the PCM.
0 Volt = open or grounded wire shorted to ground, or bad KS Module or PCM
2) Measure resitance from KS terminal to ground, should be 3300 to 4500 OHM.
If out of range the KS not properly seated or bad KS. (The KS has to make good electrical contact with the engine block, no sealant on threads, and has to be torqued to spec.
Key OFF
3) Disconnect the "D" connector from PCM, look back on pin #22 towards KS, should be ) 0 Volt, if not the wire is shorted to battey.
4) Reconnect all wires
Key ON
Backprobe at one end of the BLU wire should get 1.5 Volt. (The KS normally forces thr 5 Volts from the PCM down to 2.5 Volt.
During normal operation the KS sends an AC voltage to the KS module, the voltage depends on the loudness of the knock.
#14
Key ON
1) With the BLU wire disconnected from KS probe back towards the PCM
you should see 5 volts coming from the PCM.
0 Volt = open or grounded wire shorted to ground, or bad KS Module or PCM
2) Measure resitance from KS terminal to ground, should be 3300 to 4500 OHM.
If out of range the KS not properly seated or bad KS. (The KS has to make good electrical contact with the engine block, no sealant on threads, and has to be torqued to spec.
Key OFF
3) Disconnect the "D" connector from PCM, look back on pin #22 towards KS, should be ) 0 Volt, if not the wire is shorted to battey.
4) Reconnect all wires
Key ON
Backprobe at one end of the BLU wire should get 1.5 Volt. (The KS normally forces thr 5 Volts from the PCM down to 2.5 Volt.
During normal operation the KS sends an AC voltage to the KS module, the voltage depends on the loudness of the knock.
1) With the BLU wire disconnected from KS probe back towards the PCM
you should see 5 volts coming from the PCM.
0 Volt = open or grounded wire shorted to ground, or bad KS Module or PCM
2) Measure resitance from KS terminal to ground, should be 3300 to 4500 OHM.
If out of range the KS not properly seated or bad KS. (The KS has to make good electrical contact with the engine block, no sealant on threads, and has to be torqued to spec.
Key OFF
3) Disconnect the "D" connector from PCM, look back on pin #22 towards KS, should be ) 0 Volt, if not the wire is shorted to battey.
4) Reconnect all wires
Key ON
Backprobe at one end of the BLU wire should get 1.5 Volt. (The KS normally forces thr 5 Volts from the PCM down to 2.5 Volt.
During normal operation the KS sends an AC voltage to the KS module, the voltage depends on the loudness of the knock.
#15
When you back probe you stick the meter probe trough the back of the connector trying not to damage the insulation. You do not need to go into the PCM, just disconnect the "D" connector (the Blue connector at the PCM). The connector has 32 pins. The count starts at the bottom right corner and goes straight line up to pin 16. The next row start at the bottom right corner and goes straight line up pin 17 TO 32. Pin #22 connects to a Blue wire going towards the KS.
Use a digital VOM (Volt, Ohm meter)
Voltage tests-- Use the DC volt scale. Connect the positive (+) probe to what you want to test, The negative (-) probe is connected to ground (any metal part of the engine. The probes must touch bare metal.
Resistance test--When measuring resistance, make sure there is no power on circuit you are testing or the meter may be damaged. Place meter in Ohm scale (upside down horse shoe). Select the scale in range of what you expect to see. Connect the probes to each end of the circuit you want to measure.
Use a digital VOM (Volt, Ohm meter)
Voltage tests-- Use the DC volt scale. Connect the positive (+) probe to what you want to test, The negative (-) probe is connected to ground (any metal part of the engine. The probes must touch bare metal.
Resistance test--When measuring resistance, make sure there is no power on circuit you are testing or the meter may be damaged. Place meter in Ohm scale (upside down horse shoe). Select the scale in range of what you expect to see. Connect the probes to each end of the circuit you want to measure.
#17
Exaxtly where did you measure? At the connector on the PCM itself or at the connector on the wiring harness? Directly from the PCM, you should see 5 volts when the key is on, if not the PCM is bad, or the KS module is bad, or the PCM has a bad grond. Directly from the same pin on the wiring harness there should be 0 Volt, if you measure resistance at this same point (turn key off just in case there may be a short) you should get 3300 to 4500 Ohm, if you get less than 3300 the wire could be shorted to ground or to another wire, or the KS is bad. If you get more than 4500 ohm there could be a poor connection, bad ground on the engine, or PCM box, or a bad KS, or the KS is not making good contact with the engine.
#18
I think my Volt Ohm meter is messed up.. its saying offline for the ohms selection and even from the battery its measuring 0 volts lol
But this thing is aggravating the hell out of me... the pinging gets bad but when I put 91 instead of 89 it quiets down a lot.... I just want it to be fixed already... I might do some drastic measures when I get off work tomorrow... like just replacing parts like my KS and KS Module and go from there
Quick question the KS wire runs through the big computer then the PCM right? or does it go strait to the PCM?
But this thing is aggravating the hell out of me... the pinging gets bad but when I put 91 instead of 89 it quiets down a lot.... I just want it to be fixed already... I might do some drastic measures when I get off work tomorrow... like just replacing parts like my KS and KS Module and go from there
Quick question the KS wire runs through the big computer then the PCM right? or does it go strait to the PCM?
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