Need a guru Kohler 26hp EFI **FIXED**

[jjreds01]

Laser Z SN 332739
Bought this used and only got a couple hrs on it.
Mower ran but wouldn't charge battery.
Tested the stator it was shorted.
Pulled motor found flywheel magnets were loose.
Epoxied magnets back on flywheel +-+-+- etc
Replaced stator.
Key on, fuel pump runs, solenoid clicks no start.
Jumped switch start to trigger wire on starter. Starter works, no power to coils.
Diagnostic only shows 61.
Coils do power up for the 1-2 secs when the fuel pump runs.
Control levers switch ignition on and off as expected.
Brake switch is working per the wiring diagram and does switch ignition on when closed.
24 pin plastic ECU case.
Pin 1, 2, 15 ok. As expected.
Pin 3 and 10 are open. I didn't expect that.
I don't know if I've got 1 or 2 problems could really use some troubleshooting assistance to get the ignition working, thank you

 

[ILENGINE]

I am leaning toward the ECU not seeing input from the speed sensor. And if it can't see the engine rotating it won't fire the coils for spark.

 

[jjreds01]

I am leaning toward the ECU not seeing input from the speed sensor. And if it can't see the engine rotating it won't fire the coils for spark.

Thank you. Is there a test I can do to check it? There is no power to the coils. Pin 3 safety is open is that permission to start? And pin 10 speed sensor ground - should I see a ground there with ECU unplugged?

 

[ILENGINE]

https://resources.kohler.com/power/kohler/enginesUS/pdf/24_690_01_EN.pdf page 119 should be your speed sensor test.

 

[jjreds01]

Thanks I'll check the resistance between pin 9 and 10 on the ECU in the morning and report back

 

[jjreds01]

https://resources.kohler.com/power/kohler/enginesUS/pdf/24_690_01_EN.pdf page 119 should be your speed sensor test.

928 ohms @ ECU pin 9 & 10
928 ohms @ 3 pin sensor connector
Relay mounted to chassis clicks when turning key to start position. No starter signal, no juice to coils.
Starter is ok - works by energizing signal wire.

 

[ILENGINE]

Sounds like a safety switch is not working correctly. Park brake or direction control arms not activating safety switches for start

 

[jjreds01]

Sounds like a safety switch is not working correctly. Park brake or direction control arms not activating safety switches for start

 

[jjreds01]

That was the first thing I checked. As stated in my OP. All three switches are working. In the run position I've got power to the start relay, fuel pump relay, pin 2 on the ECU switched power. No power to coils. Fuel pump runs on key on for 1-2 sec.

 

[ILENGINE]

That was the first thing I checked. As stated in my OP. All three switches are working. In the run position I've got power to the start relay, fuel pump relay, pin 2 on the ECU switched power. No power to coils. Fuel pump runs on key on for 1-2 sec.

fuel pump, coils and injectors all get their power from the same pin of the start relay. the ECU shuts that system off after 2 seconds to prevent the fuel pump from running constantly if the engine is not running. And turns it back on with engine crank. I don't see anything on the engine side of the system that would prevent the engine from cranking. So I would be concentrating on what is preventing power to the starter solenoid in the crank position. Something is not working properly between the key switch in the start position and the starter solenoid on the engine. Did you also check the PTO switch. Whatever is preventing cranking is likely also effecting pin 3.

What happens if you ground pin 3 and then jump the solenoid to crank the engine. Pin three may be ground to run.