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.
Circuit/System Verification
The vehicle may not be equipped with all components as listed below. Use wiring schematics to determine which ignition relay supplies the ignition feed for the appropriate devices. Use the connector end view to identify the ignition circuit terminal for each of those devices.
- Ignition ON/Vehicle in Service Mode.
- Verify that the appropriate devices controlled by the KR76A Retained Accessory Power Relay 1 and KR76B Retained Accessory Power Relay 2 turn ON and OFF when switching the ignition between ON/Vehicle in Service Mode and OFF/Vehicle OFF.
- If the devices do not turn ON and OFF
Refer to Circuit/System Testing - Diagnostic A.
- Go to next step: If the devices turn ON and OFF
- If the devices do not turn ON and OFF
- Verify that the appropriate devices controlled by the KR73 Ignition Main Relay turn ON and OFF when commanding the Run/Crank Relay On and Off with a scan tool.
- If the devices do not turn ON and OFF
Refer to Circuit/System Testing - Diagnostic B.
- Go to next step: If the devices turn ON and OFF
- If the devices do not turn ON and OFF
- Verify that the appropriate devices controlled by the KR75 Engine Controls Ignition Relay turn ON and OFF when switching the ignition between ON/Vehicle in Service Mode and OFF/Vehicle OFF.
- If the devices do not turn ON and OFF
Refer to Circuit/System Testing - Diagnostic C.
- Go to next step: If the devices turn ON and OFF
- If the devices do not turn ON and OFF
- Verify that the appropriate devices controlled by the KR104A Battery Saver Relay 1 turn ON and OFF after enabling battery saver mode (transport mode).
- If the devices do not turn ON and OFF
Refer to Circuit/System Testing - Diagnostic D.
- Go to next step: If the devices turn ON and OFF
- If the devices do not turn ON and OFF
- Verify that the appropriate devices controlled by the KR104B Battery Saver Relay 2 turn ON and OFF after enabling battery saver mode (transport mode).
- If the devices do not turn ON and OFF
Refer to Circuit/System Testing - Diagnostic E.
- Go to next step: If the devices turn ON and OFF
- If the devices do not turn ON and OFF
- All OK.
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.