Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Starting Mode
When the isolation switch recognizes KL15 via the K Bus, it determines the voltage of the vehicle circuit battery.
- If the vehicle circuit battery IS sufficiently charged, it proceeds with Normal Starting.
- If the vehicle circuit battery IS NOT sufficiently charged, it proceeds with Safety Starting.
Normal Starting
- The isolation switch is open.
- Within 0.5 seconds of engine start-up the E-CAT module energizes the E-CAT heating coils (program dependent) and simultaneously signals the isolation switch that the ECATs are "On" via signal "KATON" (low signal).
- Upon completion of the heating period, the E-CAT module signals the isolation switch that the E-CATs are off (High Signal).
- Under normal conditions, the isolation switch is not closed before the heating procedure is finished.
Safety Starting:
- In response to a discharged condition of the vehicle circuit battery, the isolation switch closes to momentarily boost the vehicle circuit battery and supply all systems with starter battery voltage via the power distribution center.
This operation lasts for a maximum of 30 seconds or until confirmation of engine start up is received. (TD signal on the K Bus)
- Receiving the TD signals causes the isolation switch to immediately open for the duration of the E-CAT heating cycle.
- If the engine is not started within the 30 seconds, the isolation switch opens and remains open until KL 15 is recognized on the next start-up cycle.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.