Pinpoint Test H: The Keyless Entry Keypad Illumination Is Inoperative/Does Not Operate Correctly
Handles, Locks, Latches and Entry Systems
Pinpoint Tests
Pinpoint Test H: The Keyless Entry Keypad Illumination Is Inoperative/Does Not Operate Correctly
Refer to Wiring Diagram Set 117, Remote Keyless Entry and Alarm for schematic and connector information. Diagrams By Number
Normal Operation
The keyless entry keypad is a touch sensitive capacitive sensor. When a finger touches the keypad it changes the capacitance of the sensor in the area of the finger touch. The keypad is then able to determine which area was touched and sends a ground signal to the Remote Function Actuator (RFA) module on the corresponding reference circuit(s). The keypad only works when touched with a finger. The keyless entry keypad may not work when gloves are worn. The gloves act as an insulator and do not allow the finger to change the sensor capacitance.
When the keyless entry keypad is touched, 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 keypad is also illuminated anytime the courtesy lighting is on.
- DTC B121A:11 (Keypad Illumination Output: Circuit Short To Ground) - a continuous and on-demand DTC that sets if the RFA 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 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 module
PINPOINT TEST H: 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.
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H1 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 H8.
No
GO to H2.
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H2 CHECK THE KEYLESS ENTRY KEYPAD INPUT TO THE RFA MODULE
- Enter the following diagnostic mode on the scan tool: RFA DataLogger .
- Touch several keyless entry keypad buttons while observing the RFA module PIDs (Keypd_SW_1_2, Keypd_SW_3_4, Keypd_SW_5_6, Keypd_SW_7_8 and Keypd_SW_9_0).
- Do the PIDs display the correct values?
Yes
GO to H3.
No
GO to Pinpoint Test G. Pinpoint Test G: The Doors Do Not Lock/Unlock Using The Keyless Entry Keypad
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H3 CHECK THE RECORDED RFA MODULE DTCs FROM THE SELF-TEST
- Check the recorded results from the RFA module self-test.
- Is DTC B121A:11 present?
Yes
GO to H4.
No
GO to H6.
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H4 CHECK THE KEYLESS ENTRY KEYPAD FOR A SHORT TO GROUND
- Disconnect: Keyless Entry Keypad C500 .
- Clear the DTCs, then repeat the RFA module self-test.
- Is DTC B121A:11 recorded?
Yes
GO to H5.
No
INSTALL a new keyless entry keypad. REFER to Keyless Entry Keypad Service and Repair. TEST the system for normal operation.
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H5 CHECK THE KEYLESS ENTRY KEYPAD ILLUMINATION CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: RFA Module C2153d .
- Measure the resistance between the keyless entry keypad C500-2, circuit CPK28 (WH/GN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to H9.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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H6 CHECK FOR RFA MODULE OUTPUT
- Enter the following diagnostic mode on the scan tool: RFA DataLogger .
- Measure the voltage between the keyless entry keypad C500-2, circuit CPK28 (WH/GN), harness side and ground while active commanding the RFA module PID (KEYPD_LMP_OS) ON.
- Is the voltage greater than 11 volts?
Yes
INSTALL a new keyless entry keypad. REFER to Keyless Entry Keypad Service and Repair. TEST the system for normal operation.
No
GO to H7.
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H7 CHECK THE KEYLESS ENTRY KEYPAD CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: RFA Module C2153d .
- Measure the resistance between the keyless entry keypad C500-2, circuit CPK28 (WH/GN), harness side and the RFA module C2153d-10, circuit CPK28 (WH/GN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to H9.
No
REPAIR the circuit. TEST the system for normal operation.
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H8 CHECK THE KEYLESS ENTRY KEYPAD CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: RFA Module C2153d .
- Ignition ON.
- Observe the keypad illumination.
- Is the keypad still illuminated?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
GO to H9.
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H9 CHECK FOR CORRECT RFA MODULE OPERATION
- Disconnect all the RFA module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the RFA 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 module. REFER to Multifunction Electronic Modules Remote Function Actuator (RFA) 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.
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