Knock Sensor Code 12 could this be caused by valve train lifter noise being to loud
07-05-2007, 11:26 AM
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Knock Sensor Code 12 could this be caused by valve train lifter noise being to loud
Knock sensor wire has been replaced, also the Knock sensor, still get a code 12 on a 1985 2.4L 4x4 PU
07-09-2007, 06:59 AM
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Code 12 Fixed!
Replaced the ECU with another unit from a Furmann's Salvage in Santa Ana, CA and have yet to see the MIL illuminate since then. I have never replaced an ECU in all the time I have worked on vehicles but this one fixed it. If you have this code 12 follow these steps first.
-Backprobe the ECU KNK pin with the pos. lead and ground the other lead of the DVOM. Start the vehicle and with the meter on the Freqency / Hz scale. The readings I had with both the old ecu and the new are 0 at idle and ranging between 1 - 2/3 K Hz. A lower reading is found off idle rpm and at full throttle 2-3 thousand (K) Hz are displayed.
-If you do not get this reading you either have an issue with the wiring to the sensor or the sensor itself. Measure continuity from the terminal on the sensor connecter to the KNK pin at the ECU. If you clear this code and it still resets, just repair the wire with RG58 coax cable and solder / secure the ends.
-Checking the sensor - Use a DVOM and measure the Hz output with the pos. lead on the knk sensor terminal when installed in the engine and the other lead to ground. Tap on the intake manifold with a hammer to generate a knock / vibration. The meter should show a frequency. These sensors are quite reliable and unless the engine has been severely overheated generally do not fail.
If the wire has been repaired, the knock sensor test ok and a signal is generated to the ECU while running, the ECU is the remaining component for this code 12.
Thanks for all of your help
David
-Backprobe the ECU KNK pin with the pos. lead and ground the other lead of the DVOM. Start the vehicle and with the meter on the Freqency / Hz scale. The readings I had with both the old ecu and the new are 0 at idle and ranging between 1 - 2/3 K Hz. A lower reading is found off idle rpm and at full throttle 2-3 thousand (K) Hz are displayed.
-If you do not get this reading you either have an issue with the wiring to the sensor or the sensor itself. Measure continuity from the terminal on the sensor connecter to the KNK pin at the ECU. If you clear this code and it still resets, just repair the wire with RG58 coax cable and solder / secure the ends.
-Checking the sensor - Use a DVOM and measure the Hz output with the pos. lead on the knk sensor terminal when installed in the engine and the other lead to ground. Tap on the intake manifold with a hammer to generate a knock / vibration. The meter should show a frequency. These sensors are quite reliable and unless the engine has been severely overheated generally do not fail.
If the wire has been repaired, the knock sensor test ok and a signal is generated to the ECU while running, the ECU is the remaining component for this code 12.
Thanks for all of your help
David
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