ECM Gets 12v Puts Out 6v
01-28-2021, 09:02 AM
#1
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Join Date: Apr 2015
Posts: 675
ECM Gets 12v Puts Out 6v
I’ve tested all ECM power sources at the ECM terminals and the diagnostic k line only puts out 6v (also tested from right at the ECM)
VB(both)
SSoff
CRTN
IGNSW
Back Up (terminal 67)
all test fine at battery voltage (ssoff a few seconds after turning ign off). But my diagnostic k line is at 6.5volts. Car started acting super strange barely made it home. I feel like my ECM modules are tampered bc this just doesn’t make sense
VB(both)
SSoff
CRTN
IGNSW
Back Up (terminal 67)
all test fine at battery voltage (ssoff a few seconds after turning ign off). But my diagnostic k line is at 6.5volts. Car started acting super strange barely made it home. I feel like my ECM modules are tampered bc this just doesn’t make sense
02-01-2021, 11:54 AM
#3
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Join Date: Apr 2015
Posts: 675
02-01-2021, 04:43 PM
#4
........... kay
Did you do anything about the ground behind the radio? (errm maybe behind cluster, i have too many maxima wiring harnesses in my head).
Eg. Get a wire brush, unbolt, clean, re-attach.
Also I'm assuming your ECU is receiving 12V into the main pins from the engine harness? You weren't clear on what exactly you tested which is why I asked.... "Where are you getting 6 volts from?"
I'm assuming the hot wire on the OBDII that was clear but you make it sound like you get 6v elsewhere as well....
Did you do anything about the ground behind the radio? (errm maybe behind cluster, i have too many maxima wiring harnesses in my head).
Eg. Get a wire brush, unbolt, clean, re-attach.
Also I'm assuming your ECU is receiving 12V into the main pins from the engine harness? You weren't clear on what exactly you tested which is why I asked.... "Where are you getting 6 volts from?"
I'm assuming the hot wire on the OBDII that was clear but you make it sound like you get 6v elsewhere as well....
Last edited by aackshun; 02-01-2021 at 04:49 PM.
02-01-2021, 10:37 PM
#6
When you measured the voltage, was there something plugged into the OBD/DataLink port? It does make a difference. The FSM says you should measure pin 115 (K-line) with nothing plugged in. On 2000 & 01 cars, you should read 2 volts. On 2002 & 03 cars, you should read battery voltage.
The 6 volt reading doesn't match either spec for an empty connector. If there was something plugged in, reading the voltage with a voltmeter would not be accurate as the K line is a data communications line meaning the voltage is not constant, it is always changing. You need an oscilloscope to see the changing voltage levels. A voltmeter will give you a quasi average voltage reading.
Connect an OBD code reader to the car and see if it works. If you get information, I would not worry about the 6 volt reading you got.
The 6 volt reading doesn't match either spec for an empty connector. If there was something plugged in, reading the voltage with a voltmeter would not be accurate as the K line is a data communications line meaning the voltage is not constant, it is always changing. You need an oscilloscope to see the changing voltage levels. A voltmeter will give you a quasi average voltage reading.
Connect an OBD code reader to the car and see if it works. If you get information, I would not worry about the 6 volt reading you got.
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