01 Accent - ECU Dead - No Power?
#1
05-31-2010, 09:41 PM
01 Accent - ECU Dead - No Power?
01 Accent turns over but will not start.
No spark at the plugs, and no voltage to the harness(s) that plug in to the ignition coils.
I plugged in an OBDII tool and it can't communicate with the ECU.
I testd the OBDII tool on my Z-71 and it worked fine.
I removed the ECU and checked for voltage on the harness at all of the main pins (5 big ones). It has good ground at the center pin but I could not get any voltage reading from any of the other pins. I didn't bother to check the 50+ tiny pins.
All fuses in both the engine bay and under the dash tested fine.
I pulled the Main relay (Engine relay?) that is grounded to the side wall of the car in front of the computer and it is working fine.
Is my computer fried or not getting power?
No spark at the plugs, and no voltage to the harness(s) that plug in to the ignition coils.
I plugged in an OBDII tool and it can't communicate with the ECU.
I testd the OBDII tool on my Z-71 and it worked fine.
I removed the ECU and checked for voltage on the harness at all of the main pins (5 big ones). It has good ground at the center pin but I could not get any voltage reading from any of the other pins. I didn't bother to check the 50+ tiny pins.
All fuses in both the engine bay and under the dash tested fine.
I pulled the Main relay (Engine relay?) that is grounded to the side wall of the car in front of the computer and it is working fine.
Is my computer fried or not getting power?
Last edited by s007; 05-31-2010 at 09:43 PM.
#2
06-02-2010, 01:50 PM
My guess is the computer is fried if you can connect to an OBD-II scan tool.
IGNITION COIL
When the ignition power transistor is turned ON by a signal from the ECM, the ECM sends a signal to the ignition coil, then the primary current is shut off and a high voltage is induced in the secondary coil.
CIRCUIT DIAGRAM
HARNESS INSPECTION PROCEDURES
REMOVAL AND INSTALLATION
1.Remove the ignition fuse (Fusible link-F).
2.Disconnect the lead wire.
3.Remove the ignition coil mounting bolt and remove the ignition coil assembly.
4.Installation is the reverse order of removal.
SPARK TEST
CHECKING IGNITION COILS
1.Measure the primary coil resistance between terminals 1 and 2.
2.Measure the secondary coil resistance between the high-voltage terminal for the No.1 and No.4 cylinders, and between the high-voltage terminals for the No.2 and No.3 cylinders.
: 13.0Ω ± 15%
Be sure, when measuring the resistance of the secondary coil, to disconnect the connector of the ignition coil.
IGNITION COIL
When the ignition power transistor is turned ON by a signal from the ECM, the ECM sends a signal to the ignition coil, then the primary current is shut off and a high voltage is induced in the secondary coil.
CIRCUIT DIAGRAM
HARNESS INSPECTION PROCEDURES
REMOVAL AND INSTALLATION
1.Remove the ignition fuse (Fusible link-F).
2.Disconnect the lead wire.
3.Remove the ignition coil mounting bolt and remove the ignition coil assembly.
4.Installation is the reverse order of removal.
SPARK TEST
CHECKING IGNITION COILS
1.Measure the primary coil resistance between terminals 1 and 2.
2.Measure the secondary coil resistance between the high-voltage terminal for the No.1 and No.4 cylinders, and between the high-voltage terminals for the No.2 and No.3 cylinders.
: 13.0Ω ± 15%
Be sure, when measuring the resistance of the secondary coil, to disconnect the connector of the ignition coil.
#3
06-02-2010, 05:21 PM
I followed most of those procedures.
It's obvious the ECU isnt' sending power to the coils.
The ECU is obviosly got an issue, however, I would feel better about buying an new ECU if I could of got a voltage reading out of the harness that connects to the ECU.
Getting no voltage off that harness makes me wonder if the ECU is getting any power or not.
I wanted to know which pin supplies power to the ECU and what the power path to the ECU is.
It's obvious the ECU isnt' sending power to the coils.
The ECU is obviosly got an issue, however, I would feel better about buying an new ECU if I could of got a voltage reading out of the harness that connects to the ECU.
Getting no voltage off that harness makes me wonder if the ECU is getting any power or not.
I wanted to know which pin supplies power to the ECU and what the power path to the ECU is.
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