Pinpoint Test AC: The Keyless Entry Keypad Illumination Is Inoperative/Does Not Operate Correctly
Handles, Locks, Latches and Entry Systems - With Intelligent Access (IA)
Pinpoint Test AC: The Keyless Entry Keypad Illumination Is Inoperative/Does Not Operate Correctly
Normal Operation
When any keypad button is pressed the Remote Function Actuator (RFA) module sends voltage to the keyless entry keypad LEDs on the illumination circuit to assist the driver in entering an access code at night. The keyless entry keypad has a separate ground circuit for the LEDs.
- DTC B121A:11 (Keypad Illumination Output: Circuit Short To Ground)- a continuous and on-demand DTC that sets if the RFA (Remote Function Actuator) module detects a short to ground on the keyless entry keypad illumination circuit.
- DTC B121A:15 (Keypad Illumination Output: Circuit Short To Battery Or Open)- an on-demand DTC that sets if the RFA (Remote Function Actuator) module detects a short to voltage or open on the keyless entry keypad illumination circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Keyless entry keypad
- RFA (Remote Function Actuator) module
PINPOINT TEST AC : THE KEYLESS ENTRY KEYPAD ILLUMINATION IS INOPERATIVE/DOES NOT OPERATE CORRECTLY
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
AC1 CHECK THE KEYLESS ENTRY KEYPAD OPERATION
- Press the 7/8 and 9/0 buttons simultaneously on the keypad.
Do the doors lock using the keyless entry keypad?
Yes
GO to AC2.
No
GO to Pinpoint Test AB. Pinpoint Test AB: The Doors Do Not Lock/Unlock Using The Keyless Entry Keypad
AC2 CHECK THE RECORDED RFA (Remote Function Actuator) MODULE DTCs FROM THE SELF-TEST
- Check the recorded results from the RFA (Remote Function Actuator) module self-test.
Is DTC B121A:11 present?
Yes
GO to AC3.
No
GO to AC5.
AC3 CHECK THE KEYLESS ENTRY KEYPAD FOR A SHORT TO GROUND
- Disconnect: Keyless Entry Keypad C500.
- Clear the DTCs, then repeat the RFA (Remote Function Actuator) module self-test.
Is DTC B121A:11 recorded?
Yes
GO to AC4.
No
INSTALL a new keyless entry keypad. REFER to Keyless Entry Keypad Service and Repair. TEST the system for normal operation.
AC4 CHECK THE KEYLESS ENTRY KEYPAD ILLUMINATION CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: RFA (Remote Function Actuator) Module C2153D.
- Measure the resistance between the keyless entry keypad C500-6, circuit CPK28 (WH/GN), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to AC10.
No
REPAIR circuit CPK28 (WH/GN) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
AC5 CHECK THE KEYLESS ENTRY KEYPAD ILLUMINATION
- Ignition OFF.
- Check the keyless entry keypad illumination.
Is the keyless entry keypad illumination always on?
Yes
GO to AC9.
No
GO to AC6.
AC6 CHECK FOR RFA (Remote Function Actuator) MODULE OUTPUT
- Disconnect: Keyless Entry Keypad C500.
- Enter the following diagnostic mode on the scan tool: RFA (Remote Function Actuator) DataLogger.
- Measure the voltage between the keyless entry keypad C500-6, circuit CPK28 (WH/GN), harness side and ground while active commanding the BCM (Body Control Module) PID (KEYPD_LMP_OS) ON.
Is the voltage greater than 10 volts?
Yes
GO to AC7.
No
GO to AC8.
AC7 CHECK THE KEYPAD ILLUMINATION GROUND CIRCUIT FOR AN OPEN
- Measure the resistance between the keyless entry keypad C500-3, circuit GD133 (BK), harness side and ground.
Is the resistance less than 5 ohms?
Yes
INSTALL a new keyless entry keypad. REFER to Keyless Entry Keypad Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
REPAIR circuit GD133 (BK) for an open. CLEAR the DTCs. REPEAT the self-test.
AC8 CHECK THE KEYLESS ENTRY KEYPAD CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: RFA (Remote Function Actuator) Module C2153D.
- Measure the resistance between the keyless entry keypad C500-6, circuit CPK28 (WH/GN), harness side and the RFA (Remote Function Actuator) module C2153D-10, circuit CPK28 (WH/GN), harness side.
Is the resistance less than 5 ohms?
Yes
GO to AC10.
No
REPAIR circuit CPK28 (WH/GN) for an open. TEST the system for normal operation.
AC9 CHECK THE KEYLESS ENTRY KEYPAD CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: RFA (Remote Function Actuator) Module C2153D.
- Ignition ON.
- Observe the keypad illumination.
Is the keypad still illuminated?
Yes
REPAIR circuit CPK28 (WH/GN) for a short to voltage. TEST the system for normal operation.
No
GO to AC10.
AC10 CHECK FOR CORRECT RFA (Remote Function Actuator) MODULE OPERATION
- Disconnect all the RFA (Remote Function Actuator) module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the RFA (Remote Function Actuator) module connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new RFA (Remote Function Actuator) module. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.