DTC C0895 ESC
Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC C0895 00: Device Voltage - Electronic Suspension Control Module 12VDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
12V B+ | C0895 00 | C0895 00 | C0895 00 | -- |
Ground | -- | C0895 00 | C0895 00 | -- |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Ignition ON, Engine OFF. Parameter Normal Value: 12.6 Volts | |||
12V B+ | 0.0 Volts* | 0.0 Volts* | 12.6 Volts |
*The scan tool will not communicate with the ESC module if there is 0 Volts on the circuit. | |||
Circuit/System Description
Twelve volts is supplied to the electronic suspension control (ESC) module by the battery positive (B+) voltage circuit. The ESC module monitors the supplied voltage to determine if it is within a valid operating range. Damage to components, and incorrect data may occur if the voltage is out of range. The ESC module disables all outputs, and sets DTC C0895 00, if high or low 12V battery voltage is detected.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
12V battery voltage is outside the normal range of 9.0-15.5 volts.
Action Taken When the DTC Sets
The ESC module disables all functionality.
Conditions for Clearing the DTC
| • | A current DTC will clear when the voltage returns to the normal range. |
| • | A history DTC will clear if the condition does not return after 50 consecutive ignition cycles. |
Diagnostic Aids
| • | A high or low voltage value in multiple modules indicates a concern in the charging system. |
| • | Overcharging with a battery charger or jump starting can cause this DTC to set. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Engine running, accessories OFF, measure and record the battery voltage at the 12V battery terminals. The voltage should be between 12.6 and 15.0 volts.
- Observe the scan tool ESC module Battery Voltage Signal parameter. The reading should be between 12.6 and 15.0 volts.
| ⇒ | If not within the specified range, refer to Charging System Test . |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector of the ESC module.
- Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 ohms between the ground circuit terminal 47 and ground.
- Verify that a test lamp illuminates between the 12V B+ circuit terminal 32 of the ESC module and ground.
- If all circuits test normal, replace the ESC module.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the 12V B+ circuit for a short to ground or an open/high resistance. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ESC module replacement, setup and programming.
DTC C0895 PSCM
Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC C0895 03: Device Voltage Below Threshold - PSCM 42VDTC C0895 07: Device Voltage Above Threshold - PSCM 42V
DTC C0895 12: Device Voltage Below Minimum Threshold - PSCM 42V
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
42V+ | C0895 03, C0895 12 | C0895 03, C0895 12 | C0895 07 | -- |
Ground | -- | C0895 03, C0895 12 | -- | -- |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Engine running Parameter Normal Value: 42.00 Volts | |||
42V+ | 0.00 Volts | 42.00 Volts | -- |
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Driving over bumps Parameter Normal Range: 42.00 - 50.00 Volts | |||
PSCM Diode | -- | > 50.00 Volts | -- |
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Engine running Parameter Normal Range: 41.50 - 42.00 Volts | |||
42V+ | 0.00 Volts | 1.10 Volts | -- |
Circuit/System Description
The accessory DC power control module (APM) supplies 42 volts to the power steering control module (PSCM). The PSCM monitors the supplied intermediate voltage to determine if it is within a valid operating range. Damage to components, and incorrect data may occur if the voltage is out of range. The PSCM disables power assist and sets DTC C0895 if high or low intermediate voltage is detected.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
C0895 03
Intermediate voltage is less than 40 volts.
C0895 07
Intermediate voltage is greater than 60 volts.
C0895 12
Intermediate voltage is less than 26 volts.
Action Taken When the DTC Sets
| • | The driver information center (DIC) displays the SERVICE POWER STEERING warning message. |
| • | The PSCM limits the amount of steering assist if DTC C0895 03 is set. |
| • | The PSCM disables steering assist if DTC C0895 07 or 12 is set. |
Conditions for Clearing the DTC
| • | The DTC will pass when the intermediate voltage returns to the normal range. |
| • | A history DTC will clear if the condition does not return after 100 consecutive ignition cycles. |
Diagnostic Aids
| • | DTC C0895 will set if the APM has disabled the 42-volt conversion for any reason, such as a drive motor DTC. Diagnose any DTCs in the APM that disable the 42-volt circuit before diagnosing DTC C0895. |
| • | DTC C0895 may set if the engine stalls. Diagnose any engine stall DTCs in the ECM before diagnosing DTC C0895. |
| • | DTC C0895 may set if the serial data is interrupted. Verify that all modules can communicate, and diagnose any U-codes before diagnosing DTC C0895. |
| • | The APM may disable the 42-volt conversion if the 12-volt battery has low voltage. The PSCM will set DTC C0895 as a result. Verify that the 12-volt battery is fully charged before diagnosing DTC C0895. |
| • | If there is low voltage on the 42-volt circuit only when turning the steering wheel, the power steering motor is drawing too much current. This condition may set DTC C0895. |
| • | As the front wheels roll over bumps while driving, the power steering motor will generate voltage spikes on the 42V circuit. The PSCM contains a zener diode, to suppress any voltage spikes greater than 50 volts. The scan tool PSCM Intermediate Voltage parameter does not update fast enough to view most voltage spikes. The scan tool APM 42V Circuit Maximum parameter will record and display the maximum voltage on the 42V circuit during the current ignition cycle, including the voltage spikes caused by bump-steer. If the scan tool APM 42V Circuit Maximum parameter is greater than 50 volts after driving on a bumpy road, then the diode in the PSCM is open. This condition may set DTC C0895. |
| • | When testing for voltage at the APM 42V connector X2, use care not to cause a short between the 42V+ terminal 2 and the grounded shield which surrounds it. Use only the approved terminal probe, with the heat-shrink insulation in good condition, and only connect or disconnect the terminal probe when the 42-volt circuit is OFF. Test the terminals on the APM itself, not the harness. Do not touch the DMM or test leads while the ignition is ON. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EL-48900 HEV Safety Kit
Circuit/System Verification
- Verify that there are no DTCs in the APM that disable the 42-volt circuit, no engine-stall DTCs in the ECM, and no U-codes in any module.
- Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6-15.0 volts.
- Engine running, observe the scan tool PSCM Intermediate Voltage parameter. The voltage should be 37.5-50 volts.
- Engine running, rotate the steering wheel left and right while stationary. Observe the scan tool PSCM Intermediate Voltage parameter. The voltage should remain greater than 37.5 volts.
- Operate the vehicle on a bumpy road. Observe the scan tool APM 42V Circuit Maximum parameter. The scan tool 42V Circuit Maximum parameter should be less than 50 volts.
| ⇒ | If there are any of the specified DTCs, refer to Diagnostic Trouble Code (DTC) List - Vehicle . |
| ⇒ | If not within the specified range, refer to Charging System Test . |
| ⇒ | If not within the specified range, refer to Voltage Out Of Range At All Times. |
| ⇒ | If the voltage is less than the specified range only when turning the steering wheel, refer to Low Voltage When Turning. |
| ⇒ | If the voltage is greater than the specified range, replace the PSCM. |
Circuit/System Testing
Voltage Out Of Range At All Times
Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.
The High Voltage Disabling procedure will perform the following tasks:| • | Identify how to disable high voltage. |
| • | Identify how to test for the presence of high voltage. |
| • | Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed. |
- Ignition OFF, disconnect the 42V harness connector X2 at the APM.
- Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 3 ohms between the ground circuit terminal 1 X2 of the APM and ground.
- Ignition OFF, connect a DMM between the 42V+ circuit terminal 2 X2 of the APM and ground.
- Ignition ON, command the APM Intermediate Voltage Control ON with a scan tool. Test for 37.5-60 volts between the 42V+ circuit terminal 2 X2 terminal and ground. Command the APM Intermediate Voltage Control OFF after completing this test.
- Ignition OFF, verify that the 42V harness connector X2 is connected under the PSCM.
- If all circuits test normal, replace the PSCM.
| ⇒ | If greater than the specified range, test the APM ground circuits for an open/high resistance. If the circuits test normal, replace the APM. |
| ⇒ | If not within the specified range, replace the APM. |
| ⇒ | If the connector is not connected, connect the connector. |
Low Voltage When Turning
- Inspect the steering system for mechanical binding. The steering should have a heavy feel, if the power steering is disabled, but should not bind.
- If all circuits test normal, replace the power steering motor.
| ⇒ | If there is any mechanical binding in the steering system, refer to Steering Effort Hard in One or Both Directions . |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for APM or PSCM replacement, setup and programming |
