P1AE5

DTC P1AE5

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P1AE5
- Contactor Command Input Signal Out of Range

Diagnostic Fault Information






Typical Scan Tool Data










Circuit/System Description

The battery energy control module (BECM) uses the hybrid battery contactor commanded signal to control the high voltage (HV) contactor state. A 5-volt circuit is provided from the BECM to the hybrid powertrain control module (HPCM). The HPCM uses a pulsed width modulated (PWM) signal on the 5-volt circuit to control the contactor command. This PWM circuit is monitored by the BECM and has three operating states. The states are Contactor Open, Contactor Closed, and Contactor Invalid.

Conditions for Running the DTC

* The vehicle power mode is RUN.
* Accessory voltage is 9-18 volts.

Conditions for Setting the DTC

Contactor Commanded PWM signal is between 9 percent and 24 percent or between 36 percent and 64 percent or between 76 percent and 91 percent or the frequency of the PWM signal is not between 247 Hz to 253 Hz for 2 out of 3 seconds.

Action Taken When the DTC Sets

DTC P1AE5 is a Type C DTC.

Conditions for Clearing the DTC

DTC P1AE5 is a Type C DTC.

Diagnostic Aids

The BECM will set contactor status to OPEN when the PWM duty cycle is 65-75 percent. The BECM will set contactor status to CLOSED when the PWM duty cycle is 25-35 percent. The BECM will set contactor status to INVALID when the PWM duty cycle is out of the ranges specified for open and closed.

The frequency of the PWM signal must be between 247 Hz to 253 Hz to be valid.

Special Tools

EL-48900 HEV Safety Kit

Circuit/System Verification

1. Ignition ON, observe the DTC information with a scan tool. DTC P1AE5 should not set.

^ If DTC P0BC1 is set, refer to DTC P1AE5.

2. Ignition ON, with a scan tool the monitor hybrid battery contactor commanded PWM. The contactor commanded PWM should be 30 percent.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF. Remove the drive motor generator control module (DMCM) assembly sight shield.
2. Disconnect DMCM connector X1.
3. Turn the key ON and verify the Contactor System Request Circuit Command display indicates 100%.

^ If the display does not indicate 100% test the control circuit for a short to ground. If the circuit tests normal, replace the BECM.

4. Connect a fused jumper wire between the control circuit (X1, terminal 4) and ground and verify the Contactor System Request Circuit Command display indicates 0%.

^ If the display does not indicate 0% test the control circuit for a open or short to voltage. If the circuit tests normal, replace the BECM.
^ If the display indicates 0% replace the DMCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair. Verification Tests