Pinpoint Test G: U0100:00, U0100:87

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

Refer to MODULE COMMUNICATIONS NETWORK for schematic and connector information.

Normal Operation and Fault Conditions

The GSM communicates with the TCM through messages sent on the HS-CAN and on a private Transmission CAN.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
GSM U0100:00	Lost Communication With ECM/PCM 'A': No Sub Type Information	This DTC sets if the GSM does not receive some or all of an expected message from the TCM over HS-CAN2.
GSM U0100:87	Lost Communication With ECM/PCM 'A': Missing Message	This DTC sets if the GSM does not receive some or all of an expected message from the TCM over the private Transmission CAN

Possible Sources

Communication concern
Incorrect PMI
Circuit open or shorted
Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
TCM

G1 VERIFY THE SCAN TOOL COMMUNICATES WITH THE TCM (TRANSMISSION CONTROL MODULE)
- Ignition ON.
- Using the diagnostic scan tool, CARRY OUT the TCM self-test.
Did the TCM complete the self-test?

Yes GO to G2

No RESOLVE the TCM does not respond to the diagnostic scan tool concern. REFER to: Communications Network .

G2 CHECK THE TCM (TRANSMISSION CONTROL MODULE) FOR DIAGNOSTIC TROUBLE CODES (DTCS)
- Using the diagnostic scan tool, retrieve all diagnostic trouble codes (DTCs) from the TCM self-test.
Are any diagnostic trouble codes (DTCs) present in the TCM?

Yes RESOLVE those diagnostic trouble codes (DTCs) first. REFER to: DTC Chart and Pinpoint Tests .

No GO to G3

G3 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 the diagnostic scan tool, CARRY OUT the GSM self-test.
Are any system voltage or internal module diagnostic trouble codes (DTCs) present in the GSM?

Yes RESOLVE those diagnostic trouble codes (DTCs) first. REFER to Diagnostic Trouble Code (DTC) Chart

No GO to G4

G4 CHECK FOR OTHER CAUSES OF COMMUNICATION CONCERNS

NOTE: If new modules were installed prior to the DTC being set, the module configuration can be incorrectly set during the PMI or the PMI may not have been carried out.
- CHECK the vehicle service history for recent service actions related to the TCM or to the GSM. If recent service history is found:
  - verify correct replacement module was installed
    - HVBOM may be used to verify correct part application
  - verify the configuration of replacement module was correct
    - re-configure module using as-built data if prior configuration is suspect
  - verify the module was not obtained from a like vehicle and installed into customer vehicle
    - return the swapped module to source vehicle and obtain new replacement module
Were any causes of a communication concern found in the vehicle service history?

Yes PROGRAM or INSTALL a new module as necessary.

No GO to G5

G5 RECHECK THE GSM (GEAR SHIFT MODULE) FOR DTC (DIAGNOSTIC TROUBLE CODE) U0100:00 AND/OR U0100:87

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

Road test the vehicle.

Using a diagnostic scan tool, CARRY OUT the GSM self-test.

Is DTC U0100:00 and/or U0100:87 present in the GSM?

Yes	For U0100:00, GO to G6 For U0100:87, GO to G7

No	The concern is not present at this time. It may have been caused by a high network traffic event or by an intermittent fault condition.

G6 CHECK THE HS-CAN2 (HIGH-SPEED CONTROLLER AREA NETWORK 2) CIRCUITS FOR AN OPEN

Ignition OFF.

Disconnect GSM C2532 .

Disconnect GWM C2431 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2532-2	Courtesy of FORD MOTOR COMPANY	C2431-17
C2532-3	Courtesy of FORD MOTOR COMPANY	C2431-18

Is the resistance less than 3 ohms?

Yes

GO to G9

No	REPAIR the circuit.

G7 CHECK THE GSM (GEAR SHIFT MODULE) PRIVATE CAN (CONTROLLER AREA NETWORK) CIRCUITS FOR AN OPEN

Ignition OFF.

Disconnect GSM C2532 .

Disconnect TCM C1750A .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2532-14	Courtesy of FORD MOTOR COMPANY	C1750A-45
C2532-13	Courtesy of FORD MOTOR COMPANY	C1750A-44

Are the resistances less than 3 ohms?

Yes

GO to G8

No	REPAIR the circuit.

G8 CHECK THE GSM (GEAR SHIFT MODULE) PRIVATE CAN (CONTROLLER AREA NETWORK) CIRCUITS FOR A SHORT TO GROUND

Disconnect PCM C1232T .

Disconnect Mode select switch (MSS) C284 (if equipped).

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2532-14	Courtesy of FORD MOTOR COMPANY	Ground
C2532-13	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances greater than 10, 000 ohms?

Yes

GO to G9

No	REPAIR the circuit.

G9 CHECK FOR CORRECT TCM (TRANSMISSION CONTROL MODULE) OPERATION

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.

Ignition OFF.

Disconnect the GSM, TCM and all related in-line electrical connectors.

Using a good light source, inspect all disconnected electrical connectors for the following:
- corrosion - install new connector or terminal and clean the module pins
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- spread terminals - install new terminals as necessary

Reconnect all disconnected electrical connectors. Make sure they seat and latch correctly.

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

Road test the vehicle.

CARRY OUT the GSM self-test.

Did DTC U0100:00 and/or U0100:87 return?

Yes	CHECK OASIS for any applicable TSB. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no TSB addresses this concern, INSTALL a new TCM. REFER to: Transmission Control Module (TCM) .

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