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Pinpoint Test F: The Doors Do Not Lock/Unlock Using The Keyless Entry Keypad




Handles, Locks, Latches and Entry Systems

Pinpoint Test F: The Doors Do Not Lock/Unlock Using The Keyless Entry Keypad

Normal Operation

The Body Control Module (BCM) monitors for a ground signal on the keyless entry keypad signal input circuits. When an individual keypad button is pressed, an individual or combination of the input circuits is routed to ground. The BCM (Body Control Module) then determines which button was pressed based on which circuit(s) are grounded. The keypad has a dedicated ground circuit. Once the BCM (Body Control Module) determines that the 5-digit personal entry code, or the factory set 5-digit entry code has been entered on the keypad, the BCM (Body Control Module) then energizes the driver door unlock relay to unlock the driver door (stepped unlock enabled).

To unlock all the doors, the 3/4 button must be pressed within 5 seconds of the 5-digit code being entered.

To lock all the doors, the 5-digit code does not need to be entered. Press the 7/8 and 9/0 buttons at the same time, with the driver door closed.

The keyless entry keypad has an anti-scan feature to help prevent theft. If a valid 5-digit code is not entered within 7 attempts (35 consecutive button presses), the keyless entry keypad goes into anti-scan. In anti-scan mode, the keypad illumination flashes and all input is ignored except for pressing the 7/8 and 9/0 buttons, which will lock all doors.

- DTC B121B:01 (Keypad Input Switch: General Electrical Failure)- sets when the BCM (Body Control Module) detects a short to ground on any of the keyless entry keypad input circuits.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Keyless entry keypad

- BCM (Body Control Module)

PINPOINT TEST F : THE DOORS DO NOT LOCK/UNLOCK USING THE KEYLESS ENTRY KEYPAD

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

F1 CHECK THE BCM (Body Control Module) KEYPAD CODE

- Enter the following diagnostic mode on the scan tool: BCM (Body Control Module) DataLogger.

- Observe the BCM (Body Control Module) PIDs (KEYCODE_1stD, KEYCODE_2ndD, KEYCODE_3rdD, KEYCODE_4thD, and KEYCODE_5thD). Read and record the 5-digit factory set entry code.

- Enter the 5-digit factory set entry code on the keyless entry keypad.

Do the doors unlock?

Yes
The system is operating as designed. INFORM the customer of the correct system operation.
No
GO to F2.

F2 RETRIEVE THE RECORDED BCM (Body Control Module) DTCs FROM THE SELF-TEST

- Check for recorded BCM (Body Control Module) DTCs from the self-test.

Is DTC B121B:01 recorded?

Yes
GO to F3.
No
GO to F4.

F3 REPEAT THE BCM (Body Control Module) SELF-TEST

- Disconnect: Keyless Entry Keypad C500.

- Clear the DTCs, then repeat the BCM (Body Control Module) self-test.

Is DTC B121B:01 recorded?

Yes
GO to F9.
No
INSTALL a new keyless entry keypad. REFER to Keyless Entry Keypad . TEST the system for normal operation.

F4 CHECK THE BCM (Body Control Module) KEYPAD PIDs

- Enter the following diagnostic mode on the scan tool: BCM (Body Control Module) DataLogger.

- Press each keyless entry keypad button while observing the PIDs (KYPD_BTN_1/2, KYPD_BTN_3/4, KYPD_BTN_5/6, KYPD_BTN_7/8, and KYPD_BTN_9/0).

Do the PIDs display active when the corresponding button is pressed?

Yes
GO to F10.
No
GO to F5.

F5 CHECK THE KEYPAD GROUND CIRCUIT FOR AN OPEN

- Disconnect: Keyless Entry Keypad C500.

- Measure the resistance between the keyless entry keypad C500-3, circuit GD134 (BK/VT), harness side and ground.






Is the resistance less than 5 ohms?

Yes
GO to F6.
No
REPAIR circuit GD134 (BK/VT) for an open. TEST the system for normal operation.

F6 CHECK THE KEYLESS ENTRY KEYPAD

- Connect a fused jumper wire between the keyless entry keypad, harness side, while monitoring the BCM (Body Control Module) PIDs (KYPD_BTN_1/2, KYPD_BTN_7/8, and KYPD_BTN_9/0) as follows:

Keyless Entry Keypad Connector-Pin/Circuit Keyless Entry Keypad Connector-Pin/Circuit BCM (Body Control Module) PID C500-8 CPK29 (GY/BU) C500-3 GD134 (BK/VT) KYPD_BTN_1/2 C500-6 CPK30 (VT/GN) C500-3 GD134 (BK/VT) KYPD_BTN_7/8 C500-5 CPK31 (YE/GN) C500-3 GD134 (BK/VT) KYPD_BTN_9/0








Do the PIDs display active when the jumper wire is connected?

Yes
INSTALL a new keyless entry keypad. REFER to Keyless Entry Keypad .
No
REMOVE the jumper wire. GO to F7.

F7 CHECK THE KEYPAD INPUT CIRCUITS FOR AN OPEN

- Ignition OFF.

- Disconnect: BCM (Body Control Module) C2280C.

- Measure the resistance between the BCM (Body Control Module), harness side and the keyless entry keypad, harness side as follows:

BCM (Body Control Module) Connector-Pin Circuit Keyless Entry Keypad Connector-Pin C2280C-24 CPK29 (GY/BU) C500-8 C2280C-18 CPK30 (VT/GN) C500-6 C2280C-11 CPK31 (YE/GN) C500-5








Are the resistances less than 5 ohms?

Yes
GO to F8.
No
REPAIR the circuit in question for an open. TEST the system for normal operation.

F8 CHECK THE KEYPAD INPUT CIRCUITS FOR A SHORT TO EACH OTHER

- Measure the resistance between the keyless entry keypad, harness side as follows:

Keyless Entry Keypad Connector-Pin Circuits Keyless Entry Keypad Connector-Pin C500-8 CPK29 (GY/BU) and CPK30 (VT/GN) C500-6 C500-8 CPK29 (GY/BU) and CPK31 (YE/GN) C500-5 C500-6 CPK30 (VT/GN) and CPK31 (YE/GN) C500-5








Are the resistances greater than 10,000 ohms?

Yes
GO to F9.
No
REPAIR the circuits in question. TEST the system for normal operation.

F9 CHECK THE KEYPAD INPUT CIRCUITS FOR A SHORT TO GROUND

- Ignition OFF.

- Disconnect: BCM (Body Control Module) C2280C.

- Measure the resistance between the keyless entry keypad, harness side and ground as follows:

Connector-Pin Circuit C500-8 CPK29 (GY/BU) C500-6 CPK30 (VT/GN) C500-5 CPK31 (YE/GN)








Are the resistances greater than 10,000 ohms?

Yes
GO to F10.
No
REPAIR the circuit in question for a short to ground. CLEAR the DTCs. REPEAT the self-test.

F10 CHECK FOR CORRECT BCM (Body Control Module) OPERATION

- Disconnect all the BCM (Body Control Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the BCM (Body Control 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 BCM (Body Control 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.