Power Mode Mismatch
Power Mode Mismatch
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Circuit/System Description
The body control module (BCM) controls the ignition run relay through the control circuit by applying voltage to the ignition run relay coil control circuit. The ignition run relay is energized when the vehicle is in Service Mode, the vehicle is ON, or when a remote start is requested. This is part of the BCM's primary function in controlling the vehicle power mode.
The keyless entry control module controls the backup power for the ignition run relay through the control circuit by applying voltage to the ignition voltage circuit. This circuit is a pass-thru in the BCM and will energize the ignition circuit when the vehicle is in Service Mode, the vehicle is ON, or when a remote start is requested.
Reference Information
Schematic Reference
* Power Distribution Schematics Power Distribution Schematics
* Power Moding Schematics Power Moding Schematics
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
Description and Operation
Power Mode Description and Operation Power Mode
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Circuit/System Verification
1. Vehicle in Service Mode.
2. Verify that the device turns on and off when commanding the appropriate ignition relay ON and OFF with a scan tool.
• If the KR74 ignition run relay does not change
Refer to Circuit/System Testing - Diagnostic A.
• If the KR75 engine controls ignition relay does not change
Refer to Circuit/System Testing - Diagnostic B.
• If the KR76 retained accessory power relay does not change
Refer to Circuit/System Testing - Diagnostic C.
• If the ignition relay's change
3. All OK.
Circuit/System Testing
Danger:
High voltage enabling and disabling shall be only performed by High Voltage Qualified Technicians. The procedures for high voltage enabling/disabling can be found in the service instructions and must be strictly followed at all times. The usage of the Protocol High Voltage Disabling / Enabling is mandatory. The High Voltage Qualified Technician is responsible for the adherence to the manufacturer's service instructions as well as current national legal regulations.
Failure to follow the procedures exactly as written may result in serious injury or death.
Questions regarding training can be answered by your national training centre.
Danger:
Any hybrid/EV battery pack replacement shall be performed by High Voltage Qualified Technicians only. The replacement procedure can be found in the service instruction and must be strictly followed at all times. The High Voltage Qualified Technician is responsible for adherence to the manufacturer's service instructions as well as current national legal regulations. If the hybrid/EV battery pack needs to be replaced contact the Technical Assistance Centre for further instructions prior removal of the battery pack.
Diagnostic A
1. Vehicle OFF and all vehicle systems OFF, disconnect the KR74 ignition run relay. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 85 and ground.
• If 10 ohms or greater
1. Vehicle OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Vehicle in Service Mode.
4. Verify a test lamp illuminates between the B+ circuit terminal 30 and ground.
• If the test lamp does not illuminate and the circuit fuse is OK
1. Vehicle OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is OK and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Vehicle OFF.
2. 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 KR74 ignition run relay.
• If the test lamp illuminates
5. Connect a test lamp between the control circuit terminal 86 and the ground circuit terminal 85.
6. 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
1. Vehicle OFF, disconnect the harness connector at the K9 body control module, Vehicle in Service Mode.
2. 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.
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If the test lamp is always ON
1. Vehicle OFF, disconnect the harness connector at the K9 body control module.
2. 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
7. Verify that 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 ignition circuit.
• If the test lamp does not illuminate
8. Vehicle in Service Mode, connect a 3 A fused jumper wire between the B+ circuit terminal 30 and the ignition circuit terminal 87.
9. Verify the device is activated.
• If the device does not activate
1. Vehicle OFF, disconnect the harness connector at the device.
2. 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
3. Test for less than 2 ohms in the ignition circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the device.
• If the device activates
10. Test or replace the KR74 ignition run relay.
Diagnostic B
1. Vehicle OFF and all vehicle systems OFF, disconnect the KR75 engine controls ignition relay, Vehicle in Service Mode.
2. Verify a test lamp illuminates between the B+ circuit terminal 30 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Vehicle OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, 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
1. Vehicle OFF.
2. 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 KR75 engine controls ignition relay.
• If the test lamp illuminates
3. Verify a test lamp illuminates between the B+ circuit terminal 86 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Vehicle OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If the test lamp illuminates
4. Connect a test lamp between the B+ circuit terminal 86 and the control circuit terminal 85.
5. Verify the test lamp turns ON and OFF when commanding the engine controls ignition relay ON and OFF with a scan tool.
• If the test lamp is always OFF
1. Vehicle OFF, disconnect the harness connector at the K20 engine control module, Vehicle in Service Mode.
2. 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
3. Vehicle OFF.
4. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 engine control module.
• If the test lamp is always ON
1. Vehicle OFF, disconnect the harness connector at the K20 engine control module.
2. 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
6. Verify that 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 ignition circuit.
• If the test lamp does not illuminate
7. Vehicle in Service Mode, connect a 3 A fused jumper wire between the B+ circuit terminal 30 and the ignition circuit terminal 87.
8. Verify device is activated.
• If the device does not activate
1. Vehicle OFF, disconnect the harness connector at the device.
2. 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
3. Test for less than 2 ohms in the ignition circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the device.
• If the device activates
9. Test or replace the KR75 engine controls ignition relay.
Diagnostic C
1. Vehicle OFF and all vehicle systems OFF, disconnect the KR76 retained accessory power relay. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 41 and ground.
• If 10 ohms or greater
1. Vehicle OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Vehicle in Service Mode.
4. Verify a test lamp illuminates between the B+ circuit terminal 43 and ground.
• If the test lamp does not illuminate and the circuit fuse is OK
1. Vehicle OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is OK and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Vehicle OFF, repair the short to ground on the circuit
2. 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 KR76 retained accessory power relay.
• If the test lamp illuminates
5. Connect a test lamp between the control circuit terminal 40 and the ground circuit terminal 41.
6. 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
1. Vehicle OFF, disconnect the harness connector at the K9 body control module.
2. 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.
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If the test lamp is always ON
1. Vehicle OFF, disconnect the harness connector at the K9 body control module, Vehicle in Service Mode.
2. 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
7. Verify that a test lamp does not illuminate between the ignition circuit terminal 42 and ground.
• If the test lamp illuminates
Repair the short to voltage on the ignition circuit.
• If the test lamp does not illuminate
8. Vehicle in Service Mode, connect a 3 A fused jumper wire between the B+ circuit terminal 43 and the ignition circuit terminal 42.
9. Verify device is activated.
• If the device does not activate
1. Vehicle OFF, disconnect the harness connector at the device.
2. 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
3. Test for less than 2 ohms in the ignition circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the device.
• If the device activates
10. Test or replace the KR76 retained accessory power relay.
Component Testing
Relay Test
1. Vehicle OFF, disconnect the appropriate relay.
2. Test for 70-150 omhs between terminals 85 or 41 and 86 or 40.
• If less than 70 or greater than 150 ohms
Replace the relay.
• If between 70-150 ohms
3. Test for infinite resistance between the following terminals:
* 30 or 43 and 86 or 40
* 30 or 43 and 87 or 42
* 30 or 43 and 85 or 41
* 85 or 41 and 87 or 42
• If less than infinite resistance
Replace the relay.
• If infinite resistance
4. Test for less than 5.0 ohms between terminals 30 or 43 and 87 or 42.
• If 5.0 ohms or greater
Replace the relay.
• If less than 5.0 ohms
5. Install a 3 A fused jumper wire between relay terminal 85 or 41 and 12 V. Install a jumper wire between relay terminal 86 or 40 and ground.
6. Test for less than 5.0 ohms between terminals 30 or 43 and 87 or 42.
• If 5.0 ohms or greater
Replace the relay.
• If less than 5.0 ohms
7. All OK
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)
* Control Module References Programming and Relearning for the appropriate control module replacement, programming and setup