Diagnostic Instructions
Circuit/System Description
Remote vehicle start (RVS) begins as an RF message received by the remote control door lock receiver (RCDLR) from a keyless entry transmitter. The RVS request is sent from the RCDLR to the body control module (BCM) via serial data. The BCM monitors system
conditions such as content theft deterrent (CTD), hood ajar status, and body DTCs to determine if an RVS even will occur. If conditions are determined to be acceptable, the RVS message is sent to the engine control module/powertrain control module (ECM/PCM).
The ECM/PCM 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/PCM will initiate engine starting. During the engine run time in a RVS
attempt, before the operator enters the vehicle, the ECM/PCM may discontinue engine operation if system conditions require it or a message is received from the BCM requesting the engine be turned OFF.
Diagnostic Aids
Important: If the vehicle has a current vehicle DTC that illuminates the malfunction indicator lamp (MIL), the cause of the DTC must be diagnosed before proceeding with the Remote Vehicle Start Inoperative diagnostic.
The RVS system will not operate if any of the following conditions are present:
• | A current DTC is set that will illuminate the malfunction indicator lamp (MIL) |
• | More than two 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 or a malfunction exists in the hood ajar switch |
• | The CTD system detects an alarm trigger |
• | Excessive coolant temperature |
• | Accelerator pedal position greater than 0 percent |
• | The immobilizer system detects a malfunction |
• | A current automatic transmission shift lock control system DTC is set. |
• | A vehicle speed sensor signal is detected by the ECM/PCM. |
If a BCM has recently been replaced, ensure that the proper BCM setup procedure for enabling RVS has been performed. Refer to
Body Control Module Programming and Setup.
Reference Information
Schematic Reference
Remote Function Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Keyless Entry System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for Scan Tool Information
Circuit/System Verification
- Verify that RVS is enabled in the vehicle driver information center (DIC).
⇒ | If RVS is not enabled, use the DIC to turn on RVS functionality. Refer to the vehicle owners manual. |
- Verify that the keyless entry functions operate with all available keyless entry transmitters.
- Hazard lamps OFF, verify the scan tool BCM Hazard Switch Signal parameter is OFF.
- Hood closed, verify the scan tool BCM Hood Ajar Switch parameter is Closed.
⇒ | If not the specified value, refer to Hood Ajar Switch Circuit Malfunction. |
- Observe the scan tool ECM/PCM RVS Disable History parameters, Verify that no RVS Disable History items are present.
⇒ | If RVS disable history is present, refer to the appropriate subsection in which the malfunction occurred. |
- Verify the CTD system is operating normally and no CTD triggers exist.
Circuit/System Testing
Hood Ajar Switch Circuit Malfunction
- Ignition OFF, disconnect the harness connector at the hood ajar switch.
- Test for less than 10 ohms of resistance between the ground circuit terminal B and ground.
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
- Connect the harness connector at the hood ajar switch. Disconnect the X1 harness connector at the BCM.
- Ignition ON, verify a test lamp does not illuminate between the signal circuit terminal 26 and ground.
⇒ | If the test lamp illuminates, test the signal circuit for a short to voltage. |
- Ignition OFF, hood closed, test for 700-800 ohms of resistance between the signal circuit terminal 26 and ground.
⇒ | If not within the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the hood ajar switch. |
- Hood ajar, test for 6K-8K ohms of resistance between the signal circuit terminal 26 and ground.
⇒ | If not within the specified range, test or replace the hood ajar switch. |
- If all circuits test normal, replace the BCM.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.