Fig. 17: Identifying Fuses & Junction Block
Courtesy of DaimlerChrysler Corp.
more than 5 ohms on either circuit, repair short to ground in Dark
Green/Light Blue wire or Black/Light Blue wire. If resistance is less
than 5 ohms on either circuit, go to next step.
4) If there are no potential causes for this DTC remaining,
ACM is assumed to be defective. Replace ACM. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
LOSS OF IGNITION RUN ONLY
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. Each time a connector is disconnected, inspect
it to ensure it is in good condition. Always focus on circuit
being tested. Dirt, water and corrosion, are most common
problems in connectors. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Remove and inspect fuse No. 18 located in junction block.
If fuse is blown, go to step 5). If fuse is good, go to next step.
2) Using a voltmeter, check voltage between ground and
ignition switch output RUN circuit at fuse No. 18. If voltage is less
than 10 volts, repair open ignition switch output RUN circuit. If
voltage is more than 10 volts, go to next step.
3) Reinstall fuse No. 18. Disconnect battery and wait 2
minutes before proceeding. Disconnect ACM connector. Turn ignition on,
then reconnect battery. Using a voltmeter, check voltage between
ground and ACM connector terminal No. 15 (Dark Blue/Yellow wire). If
voltage is more than 10 volts, go to next step. If voltage is less
than 10 volts, repair open in Dark Blue/Yellow wire.
4) If there are no potential causes for this DTC remaining,
ACM is assumed to be defective. Replace ACM. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
5) Turn ignition off. Using an ohmmeter, check resistance
between ground and fused ignition switch output RUN circuit at fuse
No. 18. If resistance is more than 5 ohms, replace fuse No. 18 located
in junction block. If resistance is less than 5 ohms, go to next step.
6) Disconnect battery and wait 2 minutes before proceeding.
Disconnect ACM connector. Using an ohmmeter, check resistance between
ground and ACM connector terminal No. 15 (Dark Blue/Yellow wire). If
resistance is less than 5 ohms, repair fused ignition switch output
RUN circuit for a short to ground and replace fuse. If resistance is
more than 5 ohms, go to next step.
7) If there are no potential causes for this DTC remaining,
ACM is assumed to be defective. Replace ACM and fuse No. 18. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
LOSS OF IGNITION RUN/START
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. Each time a connector is disconnected, inspect
it to ensure it is in good condition. Always focus on circuit
being tested. Dirt, water and corrosion, are most common
problems in connectors. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Remove and inspect fuse No. 19. If fuse is blown, go to
step 5). If fuse is good, go to next step.
2) Using a voltmeter, measure ignition switch output
RUN/START circuit between fuse No. 19 and ground. If voltage is less
than 10 volts, repair open ignition switch output RUN/START circuit.
If voltage is more than 10 volts, reinstall fuse No. 19. Disconnect
battery and wait 2 minutes before proceeding. Go to next step.
3) Disconnect ACM connector. Turn ignition on. Reconnect
battery. Using a voltmeter, check voltage between ground and ACM
connector terminal No. 14 (Light Green/Yellow wire). If voltage is
less than 10 volts, repair open in Light Green/Yellow wire. If voltage
is more than 10 volts, replace ACM.
4) If there are no potential causes for this DTC remaining,
ACM is assumed to be defective. Replace ACM. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
5) Turn ignition off. Turn PAD switch to the ON position (if
equipped). Using an ohmmeter, check resistance at fused ignition
switch output RUN/START circuit between fuse No. 19 and ground. If
resistance is more than 5 ohms, replace fuse. If resistance is less
than 5 ohms, disconnect battery and wait 2 minutes before proceeding.
Disconnect ACM connector. Using an ohmmeter, check resistance between
ground and ACM connector terminal No. 14 (Light Green/Yellow wire). If\
resistance is less than 5 ohms, go to next step. If resistance is more
than 5 ohms, replace ACM and fuse No. 19.
6) Disconnect PAD switch. Using an ohmmeter, check resistance
between ground and ACM connector terminal No. 14 (Light Green/Yellow
wire). If resistance is less than 5 ohms, repair short to ground in
Light Green/Yellow wire and replace fuse No. 19. If resistance is more
than 5 ohms, replace fuse No. 19 located in junction block and go to
next step.
7) If there are no potential causes for this DTC remaining,
ACM is assumed to be defective. Replace ACM. See
AIR BAG CONTROL MODULE (ACM) under REMOVAL & INSTALLATION.
MISSING OR INVALID VIN MESSAGE
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. Each time a connector is disconnected, inspect
it to ensure it is in good condition. Always focus on circuit
being tested. Dirt, water and corrosion, are most common
problems in connectors. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Using DRB, select ENGINE PCM. If DRB displays NO RESPONSE
from PCM, go to NO RESPONSE FROM POWERTRAIN CONTROL MODULE under
VEHICLE COMMUNICATIONS. If DRB does not display NO RESPONSE from PCM
and vehicle is a Club Cab (BE) model, go to next step. If vehicle is
not a Club Cab (BE model), go step 3).
2) Using DRB, select PASSIVE RESTRAINTS, AIRBAG AND MONITORS.
Select VIN type (7th digit of VIN; VIN 2 or 3 on Club Cab). If DRB
does not display PCM VIN: BE, replace Powertrain Control Module (PCM).\
If DRB displays PCM VIN: BE, replace ACM.
3) Using DRB, select PASSIVE RESTRAINTS, AIRBAG AND MONITORS.
Select VIN type (7th digit of VIN; VIN 6 on Standard Cab). If DRB does\
not display PCM VIN: BR, replace Powertrain Control Module (PCM). If
DRB displays PCM VIN: BR, replace ACM.
NO CCD COMMUNICATION
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. Each time a connector is disconnected, inspect
it to ensure it is in good condition. Always focus on circuit
being tested. Dirt, water and corrosion, are most common
problems in connectors. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
Using DRB, read active codes. If DRB displays NO CCD
COMMUNICATION as an active code, replace ACM. If DRB does not display
NO CCD COMMUNICATION as an active code, go to
REPAIRING STORED TROUBLE CODES .
NO CLUSTER CCD MESSAGE
3) Using DRB, read stored codes. If DRB displays stored
codes, perform appropriate diagnostic test. If DRB does not display
any stored codes, system is operating properly at this time.
COMPONENT VERIFICATION TEST
Reconnect all previously disconnected components and
connectors. Turn ignition on (engine off). Fully operate system that
was malfunctioning. If system operates properly, repair is complete.
If system does not operate properly, go to appropriate diagnostic
test.
VEHICLE COMMUNICATIONS
VEHICLE COMMUNICATION PROBLEMS
NOTE: Use this test only when instructed to do so by another
diagnostic test. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
DRB Blank Screen
If DRB Screen is blank, disconnect DRB from data link
connector. Ensure good ground exists at data link connector terminal
No. 4 (Black/Tan wire). Ensure 12-volts exists at data link connector
terminal No. 16 (Pink wire). If 12-volts does not exist, check for
blown fuse No. 12 located in power distribution center. If no problems
can be found, try a different DRB cable and/or a different DRB.
No Response Condition
If no response condition from Air Bag Control Module (ACM)
exists, go to NO RESPONSE FROM AIR BAG CONTROL MODULE .
NO RESPONSE FROM AIR BAG CONTROL MODULE
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,
inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Remove and inspect fuse No. 19. If fuse is blown, go to
OPEN FUSED IGNITION SWITCH OUTPUT (RUN/START) CKT . If not, go to next
step.
2) Using a voltmeter, measure ignition switch output
RUN/START at fuse No. 19. See WIRING DIAGRAMS. If voltage is more than
10 volts, go to next step. If voltage is less than 10 volts, repair
open ignition switch output RUN/START circuit.
3) Turn ignition off and wait 2 minutes. Disconnect ACM
connector. Reinstall fuse No. 19. Turn ignition on (engine off). Using\
a voltmeter, check voltage at ACM connector terminal No. 14 (Light
Green/Yellow wire). If voltage is more than 10 volts, go to next step.
If voltage is less than 10 volts, repair open in Light Green/Yellow
wire.
4) Turn ignition off. Using DRB in ohmmeter mode, check
resistance at ACM connector terminal No. 4 (Black/Pink wire). If
resistance is more than 5 ohms, repair open in Black/Pink wire. If
resistance is less than 5 ohms, go to next step.
5) Turn ignition on (engine off). Using DRB in voltmeter
mode, check voltage at ACM connector terminal No. 21 (Violet/Brown
wire). If voltage is 1.8-2.6 volts, go to next step. If voltage is not
1.8-2.6 volts, repair open in Violet/Brown wire.
6) Using DRB in voltmeter mode, check voltage at ACM
connector terminal No. 22 (White/Black wire). If voltage is 1.8-2.6
volts, replace ACM. If voltage is not 1.8-2.6 volts, repair open in
White/Black wire.
OPEN FUSED IGNITION SWITCH OUTPUT (RUN/START) CKT
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,
inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Turn ignition on (engine off). Using DRB in voltmeter
mode, probe output side (Dark Blue wire) of fuse No. 19 located in
junction block. If voltage is less than 10 volts, repair open in Dark
Blue wire. If voltage is more than 10 volts, go to next step.
2) Turn ignition off and wait 2 minutes before proceeding.
Using DRB in ohmmeter mode, probe fused side (Light Green/Yellow wire)\
of fuse No. 19 located in junction block. If resistance is less than 5
ohms, go to next step. If resistance is more than 5 ohms, go to step
4).
3) Disconnect ACM connector. Using DRB in ohmmeter mode,
probe fused side (Light Green/Yellow wire) of fuse No. 19 located in
junction block. If resistance is less than 5 ohms, repair short to
ground in Light Green/Yellow wire an replace fuse No. 19. If
resistance is more than 5 ohms, replace ACM and fuse No. 19.
4) Turn ignition off and wait 2 minutes before proceeding.
Disconnect ACM. Using an ohmmeter, check resistance between ACM
connector terminal No. 14 (Light Green/Yellow wire) and fused side
(Light Green/Yellow wire) of fuse No. 19 located in junction block. If\
resistance is more than 5 ohms, repair open in Light Green/Yellow wire
and replace fuse No. 19. If resistance is less than 5 ohms, go to next
step.
5) Reconnect ACM connector. Turn ignition on (engine off).
replace fuse No. 19. Perform appropriate diagnostic test under
DIAGNOSTIC TESTS.
NO RESPONSE FROM POWERTRAIN CONTROL MODULE
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,
inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) If engine does not run, repair as required. If engine
runs, disconnect Powertrain Control Module (PCM) connectors. Connect a\
jumper wire between ground and PCM Gray connector terminal C30
(Violet/Brown wire). Using DRB, perform CCD bus test. If DRB does not
display SHORT TO GROUND, repair open Violet/Brown wire. If DRB
displays SHORT TO GROUND, go to next step.
2) Connect a jumper wire between ground and PCM Gray
connector terminal C28 (White/Black wire). Using DRB, perform CCD bus
test. If DRB does not display SHORT TO GROUND, repair open White/Black
wire. If DRB displays SHORT TO GROUND, replace PCM.
REPAIRING SHORT TO BATTERY
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,
Box (DRB) scan tool with appropriate cartridge for system
diagnosis. Other after-market scan tools may be used for
system diagnosis. The following procedure is for DRB scan
tool usage. Use scan tool manufacturer's instruction for
operating scan tool.
NOTE: Ensure battery is fully charged before proceeding with test.
1) Ensure ignition is off. Connect DRB to Data Link Connector
(DLC) located under driver's side of instrument panel. Using scan
tool, display all Diagnostic Trouble Codes (DTCs). Identify DTCs once
retrieved. See DIAGNOSTIC TROUBLE CODES (DTC) & DRB MESSAGES table.
2) If scan tool will not power up, check for loose cable
connections or faulty cable. If cable connections and cable are okay,
check voltage at DLC terminal No. 16. Voltage should be at least 11
volts. If voltage is not as specified, check wiring circuit and
necessary fuses. See WIRING DIAGRAMS.
3) If scan tool displays an error message, RAM TEST FAILURE,
CARTRIDGE ERROR, KEY PAD TEST FAILURE, or LOW OR HIGH BATTERY, this
indicates a scan tool failure.
4) If DTCs are displayed, perform appropriate test(s). See
DIAGNOSTIC TROUBLE CODES (DTC) & DRB MESSAGES table. If no DTCs are
displayed, see TROUBLE SHOOTING in appropriate AUTOMATIC TRANSMISSION
OVERHAUL article.
DIAGNOSTIC TROUBLE CODES (DTC) & DRB MESSAGES
\
\
\
\
\
\
\
DTC DRB-III Scan Tool Message
P0711 .................. TRANS TEMP SENSOR, NO TEMP RISE AFTER START
P0712 ............................. TRANS TEMP SENSOR VOLTAGE TO LOW
P0713 ............................ TRANS TEMP SENSOR VOLTAGE TO HIGH
P0720 ..................... LOW OUTPUT SPEED SENSOR RPM ABOVE 15 MPH
P0740 .................... TORQ CONVERTER CLU, NO RPM DROP AT LOCKUP
P0743 ........ TORQUE CONVERTER CLUTCH SOLENOID/TRANS RELAY CIRCUITS
P0748 ........... GOVERNOR PRESSURE SOL CONTROL/TRANS RELAY CIRCUITS
P0751 ....................... OD SWITCH PRESSED (LO) MORE THAN 5 MIN\
P0753 ................ TRANS 3-4 SHIFT SOLENOID/TRANS RELAY CIRCUITS
P0783 ....................... 3-4 SHIFT SOL, NO RPM DROP @ 3-4 SHIFT
P1740 (1) .......................... TCC OR O/D SOLENOID PERFORMANCE
P1756 .................... GOV PRESS NOT EQUAL TO TARGET @ 15-20 PSI
P1757 ...................... GOV PRES ABOVE 3 PSI IN GEAR WITH 0 MPH
P1762 .................... GOV PRESS SEN OFFSET VOLTS TO LOW OR HIGH
P1763 ....................... GOVERNOR PRESSURE SENSOR VOLTS TO HIGH
P1763B ...................... GOVERNOR PRESSURE SENSOR VOLTS TO HIGH
P1764 ........................ GOVERNOR PRESSURE SENSOR VOLTS TO LOW
P1765 ..................... TRANS 12 VOLT SUPPLY RELAY CNTRL CIRCUIT
P1899 .......................... P/N SWITCH STUCK IN PARK OR ON GEAR
( 1) - BR body only.
\
\
\
\
\
\
\
CLEARING DIAGNOSTIC TROUBLE CODES
After repairs have been performed, clear DTCs from PCM memory
using scan tool, following scan tool manufacturer's instructions.
NOTE: If malfunction is no longer present after DTC is stored in
PCM memory, the PCM will erase DTC after ignition has been
cycled at least 50 times. DTC may be cleared by using scan
tool. Follow scan tool manufacturer's instructions. DTCs may
also be cleared by disconnecting negative battery cable for a
period of time, but other vehicle control modules may also be
* Fused B+ feed to transmission control circuit open.
* Transmission control relay defective.
* TCC solenoid control circuit open.
* TCC solenoid control circuit shorted to ground.
* TCC wire harness defective.
* Transmission control relay output circuit open.
* Transmission control relay output circuit shorted to
ground.
* PCM defective.
* Solenoid and harness assembly defective.
Diagnostic Procedure (AN & DN Bodies)
1) Using scan tool, read DTCs. If DTC P1765 is also set, go
to DTC DTC P1765: TRANS 12-VOLT SUPPLY RELAY CNTRL CIRCUIT. If DTC
P1765 is not set, go to next step.
2) Using scan tool, perform TCC SYSTEM TEST. If engine
stalls, go to next step. If engine does not stall, go to step 5).
3) Using scan tool, clear DTCs. Start engine and check for
DTCs. Wiggle wiring harness between transmission harness connector and
PCM. If DTC P0743 resets, repair wiring harness as necessary. If DTC
P0743 does not reset, go to next step.
4) Using wiring diagram as a guide, inspect wiring and
connectors. Repair wiring harness as necessary. If wiring and
connectors are okay, see INACTIVE DTC CONDITION under SELF-DIAGNOSTIC
SYSTEM. Testing is complete.
5) Turn ignition off. Disconnect transmission solenoid
harness connector. Inspect connector and terminals for damage. Repair
as necessary. If connector and terminals are okay, turn ignition on.
Using scan tool, actuate transmission control relay. Measure voltage
between ground and transmission control relay output circuit at
transmission solenoid harness connector. If voltage does not cycle
from zero to greater than 10 volts, go to step 19). If voltage cycles
from zero to greater than 10 volts, go to next step.
6) Turn ignition off. Disconnect White PCM harness connector
C2. Inspect connector and terminals for damage. Repair as necessary.
If connector and terminals are okay, turn ignition on. Measure voltage
between ground and TCC solenoid control circuit at transmission
solenoid harness connector. If voltage is greater than 10 volts, go to
next step. If voltage is 10 volts or less, go to step 8).
7) Repair TCC solenoid control circuit for short to voltage.
Reconnect PCM and transmission solenoid harness connector. Start
engine. Using scan tool, perform TCC SYSTEM TEST. If engine stalls,
testing complete. If engine does not stall, replace PCM.
8) Reconnect transmission solenoid harness connector. Remove
transmission control relay. Inspect relay connector and terminals for
damage. Repair as necessary. If connector and terminals are okay,
measure resistance between transmission control relay output circuit
at transmission control relay connector and TCC solenoid control
circuit at White PCM harness connector C2. If resistance is 40 ohms or
less, go to step 12). If resistance is greater than 40 ohms, go to
next step.
9) Reconnect transmission control relay. Measure resistance
between ground and TCC solenoid control circuit at White PCM harness
connector C2. If resistance is less than 5 ohms, repair or replace
transmission solenoid and harness assembly. If resistance is 5 ohms or
greater, go to next step.
10) Remove transmission control relay. Measure resistance
between transmission control relay output circuit at transmission
control relay connector and TCC solenoid control circuit at White PCM
harness connector C2. If resistance is 26-40 ohms, replace PCM. If
resistance is not 26-40 ohms, go to next step.
11) Turn ignition off. Disconnect transmission solenoid
harness connector. Measure resistance of TCC solenoid control circuit
between White PCM harness connector C2 and transmission solenoid
harness connector. If resistance is less than 5 ohms, replace solenoid
and harness assembly. If resistance is 5 ohms or greater, repair open
in TCC solenoid control circuit.
12) Reconnect transmission control relay. Measure resistance
between ground and TCC solenoid control circuit at White PCM harness
connector C2. If resistance is less than 5 ohms, repair TCC solenoid
control circuit for short to ground. If resistance is 5 ohms or
greater, go to next step.
13) Remove transmission control relay. Inspect connector and
terminals for damage. Repair as necessary. If connector and terminals
are okay, measure resistance between transmission control relay output
circuit at relay and TCC solenoid control circuit at White PCM harness
connector C2. If resistance is 26-40 ohms, replace PCM. If resistance
is not 26-40 ohms, go to next step.
14) Measure resistance between TCC solenoid control circuit
and all other circuits at solenoid connector. If resistance is less
than 5 ohms between any 2 circuits, go to next step. If resistance is
not less than 5 ohms between any 2 circuits, go to step 17).
15) Reconnect transmission solenoid harness connector.
Measure resistance of TCC solenoid control circuit between ground and
White PCM harness connector C2. If resistance is less than 5 ohms,
replace solenoid and harness assembly. If resistance is 5 ohms or
greater, go to next step.
16) Repair TCC solenoid control circuit shorted to circuits
measured below 5 ohms. Perform appropriate VERIFICATION TEST VER-2A.
See TEST VER-2A. Reconnect all connectors. Start engine. Using scan
tool, perform TCC SYSTEM TEST. If engine stalls, testing complete. If
engine does not stall, replace PCM.
17) Reconnect transmission solenoid harness connector.
Measure resistance of TCC solenoid control circuit between ground and
White PCM harness connector C2. If resistance is less than 5 ohms,
replace solenoid and harness assembly. If resistance is 5 ohms or
greater, go to next step.
18) Repair or replace solenoid and harness assembly. Perform
appropriate VERIFICATION TEST VER-2A. Reconnect all connectors. Start
engine. Using scan tool, perform TCC SYSTEM TEST. If engine stalls,
testing complete. If engine does not stall, replace PCM.
19) Remove transmission control relay. Inspect connector and
terminals for damage. Repair as necessary. If connector and terminals
are okay, turn ignition on. Measure voltage between ground and B+
circuit at transmission control relay harness connector. If voltage is
10 volts or less, repair open fused B+ circuit. If voltage is greater
than 10 volts, go to next step.
20) Turn ignition off. Measure resistance of transmission
control relay output circuit between transmission control relay
connector and TCC solenoid harness connector. If resistance is greater
than 5 ohms , repair open transmission control relay output circuit.
If resistance is 5 ohms or less, go to next step.
21) Measure resistance between ground and transmission
control relay output circuit. If resistance is less than 5 ohms,
repair short to ground in transmission control relay output circuit.
If resistance is 5 ohms or greater, replace transmission control
relay.
Diagnostic Procedure (AB, BR & WJ Bodies)
NOTE: On WJ body, if all solenoid codes, P0743, P0748 and P0753 are
set, go to test DTC P1765: TRANS 12-VOLT SUPPLY RELAY CNTRL
CIRCUIT before proceeding.
1) Using scan tool, read DTCs. If DTC P1765 is also set, go
to DTC DTC P1765: TRANS 12-VOLT SUPPLY RELAY CNTRL CIRCUIT. If DTC