Ford F150 Pickup. Instruction — part 41

P1846

Transmission Transfer

Case Contact Plate A

Circuit Failure

GEM

REFER to TRANSFER CASE - GENERAL

INFORMATION - F150 PICKUP .

P1850

Transmission Transfer

Case Contact Plate B

Circuit Failure

GEM

REFER to TRANSFER CASE - GENERAL

INFORMATION - F150 PICKUP .

P1854

Transmission Transfer

Case Contact Plate C

Circuit Failure

GEM

REFER to TRANSFER CASE - GENERAL

INFORMATION - F150 PICKUP .

P1858

Transmission Transfer

Case Contact Plate D

Circuit Failure

GEM

REFER to TRANSFER CASE - GENERAL

INFORMATION - F150 PICKUP .

P1866

Transmission Transfer

Case Front Shaft Speed

Sensor Circuit Failure

GEM

REFER to TRANSFER CASE - GENERAL

INFORMATION - F150 PICKUP .

P1867

Transmission Transfer

Case Contact Plate

General Circuit Failure

GEM

REFER to TRANSFER CASE - GENERAL

INFORMATION - F150 PICKUP .

P1876

Transmission Transfer

Case 2-Wheel Drive

Solenoid Circuit Failure

GEM

REFER to TRANSFER CASE - GENERAL

INFORMATION - F150 PICKUP .

P1877

Transmission Transfer

Case 2-Wheel Drive

Solenoid Circuit Short to

Battery

GEM

REFER to TRANSFER CASE - GENERAL

INFORMATION - F150 PICKUP .

P1891

Transmission Transfer

Case Contact Plate Ground

Return Open Circuit

GEM

REFER to TRANSFER CASE - GENERAL

INFORMATION - F150 PICKUP .

P1892 Transmission Automatic 4-

Wheel Drive 4x4

Mechanical Lock Output

Circuit Failure

GEM

REFER to TRANSFER CASE - GENERAL

INFORMATION - F150 PICKUP .

P1893 Transmission Automatic 4-

Wheel Drive 4x4

Mechanical Lock Output

Circuit Short to Battery

GEM

REFER to TRANSFER CASE - GENERAL

INFORMATION - F150 PICKUP .

U1011

SCP (J1850) Invalid or

Missing Data for Engine

Air Intake

AFCM

REFER to appropriate SELF-DIAGNOSTICS article.

U1071

SCP (J1850) Invalid or

Missing Data for Engine

Sensors

AFCM

REFER to appropriate SELF-DIAGNOSTICS article.

U1073

SCP (J1850) Invalid or

Missing Data for Engine

Coolant

AFCM

REFER to appropriate SELF-DIAGNOSTICS article.

2003 Ford Pickup F150

2003 ACCESSORIES AND EQUIPMENT Multifunction Electronic Module - F150 Pickup

CENTRAL TIMER MODULE (CTM)/GENERIC ELECTRONIC MODULE (GEM)

Special Tool(s)

Fig. 2: Identifying (CTM)/(GEM) Special Tool(s)

U1260 SCP (J1850) Single Ended

(+) Circuit Failure

AFCM

REFER to appropriate SELF-DIAGNOSTICS article.

U1261 SCP (J1850) Single Ended

(-) Circuit Failure

AFCM

REFER to appropriate SELF-DIAGNOSTICS article.

U1262

SCP (J1850)

Communication Bus Fault

AFCM

REFER to appropriate SELF-DIAGNOSTICS article.

U1341

SCP (J1850) Invalid or

Missing Data for Function

Read Vehicle Speed

AFCM

REFER to appropriate SELF-DIAGNOSTICS article.

U2015

Signal Link Fault (Non

SCP)

AFCM

REFER to appropriate SELF-DIAGNOSTICS article.

2003 Ford Pickup F150

2003 ACCESSORIES AND EQUIPMENT Multifunction Electronic Module - F150 Pickup

Courtesy of FORD MOTOR CO.

Principles of Operation

The following is list of GEM/CTM controlled functions:

z

wipers/washers (front/rear)

z

warning chimes

z

battery saver

z

illuminated entry and courtesy lamps

z

accessory delay

z

driver power window (GEM only)

The generic electronic module (GEM) constantly monitors its subsystems for concerns. If a concern is found in
one of the subsystems, the GEM will record the concern in the form of a diagnostic trouble code (DTC). The
ignition switch position is very important to the GEM function. Often times, erratic or unexpected GEM
function can be traced to concerns with ignition switch inputs.

Ignition Switch Positions

The position of the ignition switch is very important to correct GEM operation. The following is a brief
description of five ignition switch positions.

When the ignition switch is in the RUN position, battery voltage should be present at the GEM RUN and
RUN/ACC input terminals.

When the ignition switch is in the ACC position, battery voltage should be present at the GEM RUN/ACC input
terminal only.

When the ignition switch is in the START position, battery voltage should be present at the GEM start/clutch
depressed input.

The GEM module does not have an OFF or LOCK switch state input. The GEM will assume the OFF or LOCK
position when there are no RUN, ACC, or START signals present.

Inspection and Verification

1. Verify the customer concern by operating the system.

2. Visually inspect for obvious signs of electrical damage.

Visual Inspection Chart

NOTE:

Each vehicle has either a generic electronic module (GEM) or central timer
module (CTM) depending on option content. Upon installation of a new GEM,
the module must be reconfigured. Refer to MODULE CONFIGURATION-F150

2003 Ford Pickup F150

2003 ACCESSORIES AND EQUIPMENT Multifunction Electronic Module - F150 Pickup

Fig. 3: Multifunction Electronic Modules Visual Inspection Chart
Courtesy of FORD MOTOR CO.

3. If the concern remains after the inspection, connect the diagnostic tool to the data link connector (DLC)

located beneath the instrument panel and select the vehicle to be tested from the diagnostic tool menu. If
the diagnostic tool does not communicate with the vehicle:

z

check that the program card is correctly installed.

z

check the connections to the vehicle.

z

check the ignition switch position.

4. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool instruction.

5. Carry out the DATA LINK DIAGNOSTICS test. If the diagnostic tool responds with:

z

CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to MODULE
COMMUNICATIONS NETWORK-F150 .

z

NO RESPONSE/NOT EQUIP for GEM, go to pinpoint Test A.

z

SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the
continuous DTCs and carry out self-test diagnostics for the GEM.

6. If the DTCs retrieved are related to the concern, go to the Diagnostic Trouble Code (DTC) Index to

continue diagnostics.

7. If no DTCs related to the concern are retrieved, refer to the appropriate article continue diagnostics.

Symptom Chart

SYMPTOM CHART

Condition

Possible Sources

Action

No communication with the Generic Electronic
Module (GEM)/Central Timer Module (CTM)

z

Battery junction box
(BJB) fuse 103 (50A)

z

Central junction box
(CJB) fuse 15 (5A)

GO to PINPOINT

TEST A .

2003 Ford Pickup F150

2003 ACCESSORIES AND EQUIPMENT Multifunction Electronic Module - F150 Pickup