Circuit/System Testing
Diagnostic A
- Ignition OFF and all vehicle systems OFF, disconnect the KR76 Retained Accessory Power Relay. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 10 Ω between the ground circuit terminal 86 and ground.
- If 10 Ω or greater
- Ignition OFF.
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground connection.
- If less than 10 Ω
- Ignition ON.
- Verify a test lamp illuminates between the B+ circuit terminal 87 and ground.
- If the test lamp does not illuminate
Replace the X53A Fuse Block - Rear Body
- If the test lamp illuminates
- If the test lamp does not illuminate
- Connect a test lamp between the control circuit terminal 85 and the ground circuit terminal 86.
- Verify the test lamp turns ON and OFF when commanding the Accessory/Retained Accessory Power Relay On and Off with a scan tool.
- If the test lamp is always OFF
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K9 Body Control Module.
- If the test lamp is always ON
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module, ignition ON.
- Test for less than 1 V between the control circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K9 Body Control Module.
- If the test lamp turns ON and OFF
- Verify that a test lamp does not illuminate between the ignition circuit terminal 30 and ground.
- If the test lamp illuminates
Repair the short to voltage on the ignition circuit
- If the test lamp does not illuminate
- If the test lamp illuminates
- Ignition ON, connect a 20 A fused jumper wire between the B+ circuit terminal 87 and the ignition circuit terminal 30.
- Verify device is activated.
- If the device does not activate
- Ignition OFF, disconnect the harness connector at the device.
- Test for infinite resistance between the ignition circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the ignition circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the device.
- If the device activates
- Test or replace the KR76 Retained Accessory Power Relay.
Diagnostic B
- Ignition OFF and all vehicle systems OFF, disconnect the KR73 Ignition Main Relay. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 10 Ω between the ground circuit terminal 85 and ground.
- If 10 Ω or greater
- Ignition OFF.
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground connection.
- If less than 10 Ω
- Ignition ON.
- Verify a test lamp illuminates between the B+ circuit terminal 30 and ground.
- If the test lamp does not illuminate
Replace the X50A Fuse Block - Underhood
- If the test lamp illuminates
- If the test lamp does not illuminate
- Connect a test lamp between the control circuit terminal 86 and the ground circuit terminal 85.
- Verify the test lamp turns ON and OFF when commanding the Run/Crank Relay On and Off with a scan tool.
- If the test lamp is always OFF
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K9 Body Control Module.
- If the test lamp is always ON
- Ignition OFF and all vehicle systems OFF, remove the test lamp, disconnect the K9 Body Control Module, ignition ON.
- Test for less than 1 V between the control circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K9 Body Control Module.
- If the test lamp turns ON and OFF
- Verify that a test lamp does not illuminate between the ignition circuits listed below and ground.
- Ignition circuit terminal 87
- Ignition circuit terminal 87A
- If the test lamp illuminates
Repair the short to voltage on the ignition circuit.
- If the test lamp does not illuminate
- Ignition ON, connect a 40 A fused jumper wire between the B+ circuit terminal 30 and the ignition circuits listed below.
- Ignition circuit terminal 87
- Ignition circuit terminal 87A
- Verify the device is activated.
- If the device is not activated
- Ignition OFF, disconnect the harness connector at the device.
- Test for infinite resistance between the ignition circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the ignition circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the device.
- If the device activates
- Test or replace the KR73 Ignition Main Relay.
Diagnostic C
- Ignition OFF and all vehicle systems OFF, disconnect the KR146 Exhaust Flow Control Valve Relay. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 10 Ω between the ground circuit terminal 86 and ground.
- If 10 Ω or greater
- Ignition OFF.
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground connection.
- If less than 10 Ω
- Ignition ON.
- Verify a test lamp illuminates between the B+ circuit terminal 87 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF, remove the test lamp.
- Test for less than 2 Ω in the B+ circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, verify the fuse is good and there is voltage at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
- Ignition OFF, remove the test lamp.
- Test for infinite resistance between the ignition circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance, replace the KR146 Exhaust Flow Control Valve Relay.
- If the test lamp illuminates
- Connect a test lamp between the control circuit terminal 86 and the ground circuit terminal 85.
- Verify the test lamp turns ON and OFF when commanding the Run/Crank Relay On and Off with a scan tool.
- If the test lamp is always OFF
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K9 Body Control Module.
- If the test lamp is always ON
- Ignition OFF and all vehicle systems OFF, remove the test lamp, disconnect the K9 Body Control Module, ignition ON.
- Test for less than 1 V between the control circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K9 Body Control Module.
- If the test lamp turns ON and OFF
- Verify a test lamp does not illuminate between the ignition circuit terminal 30 and ground.
- If the test lamp illuminates
Repair the short to voltage on the ignition circuit.
- If the test lamp does not illuminate
- If the test lamp illuminates
- Ignition ON, connect a 20 A fused jumper wire between the B+ circuit terminal 30 and the ignition circuit terminal 87.
- Verify the device is activated.
- If the device is not activated
- Ignition OFF, disconnect the harness connector at the device.
- Test for infinite resistance between the ignition circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the ignition circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the device.
- If the device activates
- Test or replace the KR73 Ignition Main Relay.
Diagnostic D
- Ignition OFF and all vehicle systems OFF, disconnect the KR75 Engine Controls Ignition Relay, ignition ON.
- Verify a test lamp illuminates between the B+ circuit terminal 30 and ground.
- If the test lamp does not illuminate
Replace the X50A Fuse Block - Underhood
- If the test lamp illuminates
- If the test lamp does not illuminate
- Verify a test lamp illuminates between the B+ circuit terminal 85 and ground.
- If the test lamp does not illuminate
Replace the X50A Fuse Block - Underhood
- If the test lamp illuminates
- If the test lamp does not illuminate
- Connect a test lamp between the B+ circuit terminal 85 and the control circuit terminal 86.
- Verify the test lamp turns ON and OFF when switching the ignition ON and OFF.
- If the test lamp is always OFF
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
- Test for less than 1 V between the control circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
- Ignition OFF.
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- If the test lamp is always ON
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K20 Engine Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance, replace the K20 Engine Control Module.
- If the test lamp turns ON and OFF
- Verify a test lamp does not illuminate between the ignition circuit terminal 87 and ground.
- If the test lamp illuminates
Repair the short to voltage on the circuit.
- If the test lamp does not illuminate
- If the test lamp illuminates
- Ignition ON, connect a 40 A fused jumper wire between the B+ circuit terminal 30 and the ignition circuit terminal 87.
- Verify device is activated.
- If the device is not activated
- Ignition OFF, disconnect the harness connector at the device.
- Test for infinite resistance between the ignition circuit terminal 87 and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the ignition circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the device.
- If the device activates
- Test or replace the KR75 Engine Controls Ignition Relay.
Diagnostic E
- Ignition OFF and all vehicle systems OFF, disconnect the KR104A Battery Saver Relay 1. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 10 Ω between the ground circuit terminal 6 and ground.
- If 10 Ω or greater
- Ignition OFF.
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground connection.
- If less than 10 Ω
- Ignition ON.
- Verify a test lamp illuminates between the B+ circuit terminal 5 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF, remove the test lamp.
- Test for less than 2 Ω in the B+ circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
- Ignition OFF, remove the test lamp.
- Test for infinite resistance between the B+ circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance, replace the KR104B Battery Saver Relay 1.
- If the test lamp illuminates
- Enable battery saver mode (transport mode).
- Ignition OFF.
- Connect a test lamp between the control circuit terminal 1 and ground.
- Verify the test lamp momentarily flashes ON and OFF when turning the ignition ON.
- If the test lamp is always OFF
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K9 Body Control Module.
- If the test lamp is always ON
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module, ignition ON.
- Test for less than 1 V between the control circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K9 Body Control Module.
- If the test lamp turns ON and OFF
- Connect a test lamp between the control circuit terminal 2 and ground.
- Verify the test lamp momentarily flashes ON and OFF after turning the ignition OFF.NOTE:
It may take up to 1 min after the ignition is switched OFF and retained accessory power is disabled before the body control module sends a command to unlatch the relay.
- If the test lamp is always OFF
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K9 Body Control Module.
- If the test lamp is always ON
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module, ignition ON.
- Test for less than 1 V between the control circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K9 Body Control Module.
- If the test lamp turns ON and OFF
- Verify that a test lamp does not illuminate between the ignition circuit terminal 3 and ground.
- If the test lamp illuminates
Repair the short to voltage on the ignition circuit
- If the test lamp does not illuminate
- If the test lamp illuminates
- Ignition ON, connect a 30 A fused jumper wire between the B+ circuit terminal 5 and the ignition circuit terminal 3.
- Verify device is activated.
- If the device does not activate
- Ignition OFF, disconnect the harness connector at the device.
- Test for infinite resistance between the ignition circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the ignition circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the device.
- If the device activates
- Test or replace the KR104A Battery Saver Relay 1.
Diagnostic F
- Ignition OFF and all vehicle systems OFF, disconnect the KR104B Battery Saver Relay 2. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 10 Ω between the ground circuit terminal 6 and ground.
- If 10 Ω or greater
- Ignition OFF.
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground connection.
- If less than 10 Ω
- Ignition ON.
- Verify a test lamp illuminates between the B+ circuit terminal 3 and ground.
- If the test lamp does not illuminate
Replace the X53A Fuse Block - Rear Body.
- If the test lamp illuminates
- If the test lamp does not illuminate
- Enable battery saver mode (transport mode).
- Ignition OFF.
- Connect a test lamp between the control circuit terminal 1 and ground.
- Verify the test lamp momentarily flashes ON and OFF when turning the ignition ON.
- If the test lamp is always OFF
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K9 Body Control Module.
- If the test lamp is always ON
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module, ignition ON.
- Test for less than 1 V between the control circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K9 Body Control Module.
- If the test lamp turns ON and OFF
- Connect a test lamp between the control circuit terminal 2 and ground.
- Verify the test lamp momentarily flashes ON and OFF after turning the ignition OFF.NOTE:
It may take up to 1 min after the ignition is switched OFF and retained accessory power is disabled before the body control module sends a command to unlatch the relay.
- If the test lamp is always OFF
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K9 Body Control Module.
- If the test lamp is always ON
- Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module, ignition ON.
- Test for less than 1 V between the control circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K9 Body Control Module.
- If the test lamp turns ON and OFF
- Verify that a test lamp does not illuminate between the ignition circuit terminal 5 and ground.
- If the test lamp illuminates
Repair the short to voltage on the ignition circuit
- If the test lamp does not illuminate
- If the test lamp illuminates
- Ignition ON, connect a 20 A fused jumper wire between the B+ circuit terminal 3 and the ignition circuit terminal 5.
- Verify device is activated.
- If the device does not activate
- Ignition OFF, disconnect the harness connector at the device.
- Test for infinite resistance between the ignition circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2 Ω in the ignition circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the device.
- If the device activates
- Test or replace the KR104B Battery Saver Relay 2.