Pinpoint Test F: The GSM (Gear Shift Module) Center Button Does Not Operate Properly

WARNING: This page is about a different variant/trim than selected.

Refer to TRANSMISSION CONTROLS - HF45 for schematic and connector information.

Normal Operation and Fault Conditions

The rotary gear shift knob contains three internal contact switches under the center button. When the button is pressed, the 3 switches send a signal to the GSM. The GSM sets a DTC if the three switch signals do not agree, or if it detects a possible stuck switch.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
GSM P07EC:00	Transmission Range Multi-Function Select Circuit: No Sub Type Information	This DTC sets if 1 of the 3 contacts of the center button does not agree with the other 2 contacts.
GSM P07ED:00	Transmission Range Multi-Function Select Circuit Stuck: No Sub Type Information	This DTC sets if the GSM detects the center button has been pressed for more than 60 seconds.

Possible Sources

Debris or foreign material on or near the GSM center button
Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
GSM
The customer holding the center button down

F1 INSPECT THE GSM (GEAR SHIFT MODULE) CENTER BUTTON

Inspect the GSM center button for debris or foreign materials that could cause it to stick.

Press and release the GSM center button. Make sure it moves freely.

Is the M button free of debris and foreign material, and does it move freely?

Yes

GO to F2

No	CLEAN any debris or foreign material from the button. If the button still sticks after cleaning it, INSTALL a new GSM. REFER to: Gear Shift Module (GSM) . Otherwise, GO to F2

F2 CHECK THE GSM (GEAR SHIFT MODULE) CENTER BUTTON PID (PARAMETER IDENTIFICATION) STATUS
- Access the GSM and monitor the SBW_SLM_SW_1PID
- Access the GSM and monitor the SBW_SLM_SW_2PID
- Access the GSM and monitor the SBW_SLM_SW_3PID
- Press and release the GSM center button while monitoring the PIDs.
Do all the switch PID readings change correctly as the center button is pressed and released?

Yes GO to F3

No GO to F4

F3 CHECK THE GSM (GEAR SHIFT MODULE) FOR DIAGNOSTIC TROUBLE CODES (DTCS)

NOTE: If a GSM self-test is carried out, the driver door must be fully closed. A false P166B DTC may set if the driver door is not fully closed during the self-test.

Using a diagnostic scan tool, clear all diagnostic trouble codes (DTCs) from the GSM.

Ignition OFF.

Ignition ON.

Wait 2 minutes.

Repeat the following steps 20 times:
- Press and hold the center button for 3 seconds.
- Release the center button for 3 seconds.

Using a diagnostic scan tool, carry out the GSM self-test.

Is DTC P07EC:00 and/or P07ED:00 present?

Yes

GO to F4

No	The GSM center button is operating properly at this time. The concern may have been caused by debris or interference on the GSM center button, or by the customer holding the button down.

F4 CHECK FOR CORRECT GSM (GEAR SHIFT MODULE) OPERATION

Ignition OFF.

Disconnect and inspect the GSM connector.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Connect the GSM connector. Make sure it seats and latches correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	CHECK for an applicable TSB, GSB, SSM, or FSA. If a service bulletin exists for this concern, discontinue this test and follow bulletin instructions. If none address this concern, INSTALL a new GSM. REFER to: Gear Shift Module (GSM) .

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.