Keyless Entry System Malfunction (With ATH)
Keyless Entry System Malfunction (with ATH)
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.
Diagnostic Fault Information
Circuit/System Description
The keyless entry antennas are used as short range low frequency (LF) transmitters. As a vehicle with locked doors is approached with a key fob and the exterior door handle is pulled, the keyless entry antenna transmitter broadcasts a challenge to the key fob in an approximately 1 meter range. If the response from the key fob via radio frequency (RF) is valid, the locked door will be passively unlocked/unlatched and allow the door to be opened. The front doors will open with one pull of the front door handle. The rear doors will unlock with the first pull of the door handle and unlatch with the second pull of the door handle. A low transmitter battery or radio frequency (RF) interference from aftermarket devices such as 2-way radios, power inverters, cellular phone chargers, computers, etc. may cause a system malfunction. High RF traffic areas, such as gas stations which use pay-at-the-pump RF transponders, may also cause interference that could lead to a malfunction.
Reference Information
Schematic Reference
Remote Function Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Keyless Entry System Description and Operation (With ATH) Keyless Entry System Description and Operation (Without ATH)
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Special Tools
J43241 Keyless Entry Tester
Circuit/System Verification
1. Ignition ON, observe the scan tool Exterior Driver Door Handle Switch, Exterior Passenger Door Handle Switch, and Trunk Release Switch parameters while operating their respective release handle/touch pad. The parameter should change between Active and Inactive as commanded.
2. If the parameter does not cycle between the specified values, refer to Power Door Locks Malfunction.
3. With the vehicle locked, attempt to passively unlock and access the vehicle at the left door, right door, and rear compartment by approaching the vehicle with a valid transmitter and operating their respective release handle/touch pad. Each door and the rear compartment should unlock/unlatch and open.
4. If both doors and the rear compartment do not unlock/unlatch and open, refer to Passive Transmitter Malfunction.
5. If only one door or the rear compartment does not unlock/unlatch and open, refer to Antenna Circuit Malfunction.
Circuit/System Testing
Passive Transmitter Malfunction
Place the keyless entry transmitter on the J 43241 and approach the vehicle. Operate the release handle/touch pad. Verify that the J 43241 sounds a tone.
Antenna Circuit Malfunction
1. Ignition OFF, disconnect the harness connector at the inoperative keyless entry antenna.
2. Ignition ON, verify a test lamp does not illuminate between the signal circuit terminal 1 and ground.
3. If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the keyless entry control module.
4. Install a DMM between the signal circuit terminal 1 and the low reference circuit terminal 2. Set the DMM to capture AC voltage using the MIN MAX function.
5. Operate the release handle/touch pad. Verify the DMM captured an alternating voltage signal.
6. If an alternating voltage was not captured, test the signal circuit and the low reference circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the keyless entry control module.
7. If all circuits test normal, test or replace the keyless entry antenna.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Front Side Door Outside Handle Replacement (Base)
- Control Module References for keyless entry control module replacement, setup and programming