Remote Vehicle Start Malfunction

Remote Vehicle Start Malfunction

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 each diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

Remote start begins as an radio frequency message received by the body control module (BCM) from a keyless entry transmitter. The BCM monitors system conditions such as content theft deterrent, hood ajar status, and body DTCs to determine if a remote start event will occur. If conditions are determined to be acceptable, the remote start message is sent to the engine control module (ECM). The ECM monitors system conditions such as engine control parameters and the immobilizer system to determine if engine starting will be allowed. If conditions are acceptable, the ECM will activate the appropriate vehicle systems.

Diagnostic Aids

* A remote start event will not always start the vehicle engine. If the high voltage battery state of charge is sufficient to operate the vehicle systems or the vehicle is plugged in, the engine will not start.
* If the vehicle has a current vehicle DTC that illuminates the malfunction indicator lamp, the cause of the DTC must be diagnosed before proceeding with the remote start malfunction diagnostic.

Reference Information
Schematic Reference

Remote Function Schematics [1][2]Electrical Diagrams
Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1 A4
Description and Operation

Keyless Entry System Description and Operation Description and Operation
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 Control Module Referencesfor scan tool information

Circuit/System Verification

1. Verify that remote start is enabled through vehicle personalization.

• If remote start is not enabled, use vehicle personalization to turn on remote start functionality. Refer to the vehicle owners manual.

2. Verify that the keyless entry functions operate with all available keyless entry transmitters.

• If the keyless entry system does not function properly, refer to Keyless Entry System Malfunction Keyless Entry System Malfunction.

3. Verify none of the following conditions exist on the vehicle:

* A DTC that illuminates the malfunction indicator lamp (MIL) is set
* A propulsion system DTC is set
* A high voltage system DTC is set
* The vehicle is in valet mode
* More than 2 remote start attempts have occurred
* The hazard switch is in the ON position
* A current hazard switch DTC is set
* The vehicle hood is ajar
* A current hood ajar DTC is set
* The content theft deterrent system detects an alarm trigger
* Excessive engine RPM
* Excessive coolant temperature
* Accelerator pedal position greater than 0 percent
* Vehicle not in park
* Immobilizer system malfunction
* An automatic transmission shift lock control system DTC is set.
* A vehicle speed sensor signal is detected by the ECM.

• If any of the conditions are present, refer to the appropriate subsystem for diagnosis.