2008 SUZUKI SWIFT isc

Downloaded from www.Manualslib.com manuals search engine 5A-74 Automatic Transmission/Transaxle:
DTC P1778: TCM Lost Communication with BCM (Reception Error)S7RS0B5104041
Wiring Diagram
Refer to “DTC P1774: CAN Communication Bus Off”.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
1) Connect scan tool to DLC with ignition switch OFF.
2) Clear DTC.
3) Start engine and run it for 1 min. or more.
4) Check DTC.
DTC Troubleshooting
NOTE
Upon completion of inspection and repair work, perform “DTC Confirmation Procedure:” “DTC
Confirmation Procedure” and confirm that the trouble has been corrected.

DTC detecting condition Trouble area
Reception error of communication data fo r BCM is detected more than specified
time continuously. •ECM
•TCM
•BCM
• ABS control module
• CAN circuit
Step
Action YesNo
1 Was “A/T System Check” performed? Go to Step 2.Go to “A/T System
Check”.
2 Control module connector check
1) Check connection of connectors of all control modules
communicating by means by means of CAN.
2) Recheck DTC.
Is there DTC P1778? Go to Step 3.
Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
3 DTC check in BCM (bus off)
1) Check BCM for DTC referring to “DTC Check in Section
10B”.
Is there DTC U1073? Go to “DTC U1073 (No.
1073): Control Module
Communication Bus Off
in Section 10B”.
Go to Step 4.
4 DTC check in ABS control module
1) Check ABS control module for DTC referring to “DTC
Check in Section 4E”.
Is there DTC U1100? Go to “DTC U1100: Lost
Communication with
ECM (Reception Error)
in Section 4E”.
Go to Step 5.
5 DTC check in ECM
1) Check ECM for DTC referring to “DTC Check in Section
1A”.
Is there DTC P1678? Check BCM power and
ground circuit. If circuit
is OK, substitute a
known-good BCM and
recheck.Go to Step 6.
6 CAN communication circuit check
1) Turn ignition switch to OFF position.
2) Disconnect connectors of all control modules
communicating by means of CAN.
3) Check CAN communication circuit between control modules for open, short and high resistance.
Is each CAN communication circuit in good condition? Check TCM power and
ground circuit. If circuit
is OK, substitute a
known-good TCM and
recheck.
Repair circuit.

Downloaded from www.Manualslib.com manuals search engine Automatic Transmission/Transaxle: 5A-77
DTC TroubleshootingStep Action Yes No 1 Was “A/T System Check” performed? Go to Step 2. Go to “A/T System
Check”.
2 Check TCC solenoid valve resistance
1) Turn ignition switch to OFF position.
2) Disconnect valve body harness connector (1), (2) on
automatic transaxle.
3) Check for proper connection to terminal at “WHT/BLU” and “WHT/BLK” circuit.
4) Check resistance of TCC solenoid valve.
TCC solenoid valve resistance
Between terminals of transaxle side valve body
harness connector: 5.0 – 5.6 Ω at 20 °C (68 °F)
Between terminals of transaxle side valve body
harness connector and transaxle: Infinity
Is check results satisfactory? Go to Step 3. Replace TCC solenoid
valve or valve body
harness.
3 Check for pressure control solenoid valve circuit
1) Disconnect TCM connectors.
2) Check for proper connection to TCM at terminals “C34-
3” and “C34-5”. If connection is OK, check circuit for
open, short and high resistance for the following circuit.
• Between “C34-3” terminal of TCM connector and “WHT/BLK” terminal of valve body harness connector.
• Between “C34-4” terminal of TCM connector and “WHT/BLU” terminal of valve body harness connector.
Are they in good condition? Intermittent trouble or
faulty TCM. Check for
intermittent referring to
“Intermittent and Poor
Connection Inspection
in Section 00”. If OK,
substitute a known-
good TCM and recheck.
If OK, substitute a
known-good TCM and
recheck.
Repair “WHT/BLU” and/
or “WHT/BLK” circuit.
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10 5
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2Check TCC solenoid valve circuit for IG short
1) Connect valve body harness connector.
2) Disconnect TCM connectors.
3) Check for proper connection to TCM at terminal “C34-3”
and “C34-5”.
4) If connection is OK, turn ignition switch ON and measure voltage between terminal “C34-3” of disconnected
harness side TCM connector and ground between
terminal “C34-5” of disconnected harness side TCM
connector and ground.
Are voltage 1 V or less? Go to Step 3. “WHT/BLU” or “WHT/
BLK” circuit shorted to
power circuit.
3 Check TCC lock-up pressure control solenoid valve
resistance
1) Turn ignition switch OFF.
2) Disconnect valve body harness connector (1), (2) on
automatic transaxle.
3) Check for proper connection to solenoid at “WHT/BLU” and “WHT/BLK” circuits.
4) Check resistance of TCC lock-up pressure control
solenoid valve.
TCC lock-up pressure control solenoid valve
resistance
Between terminals of transaxle side valve body
harness connector: 5.0 – 5.6 Ω at 20 °C (68 °F)
Between terminals of transaxle side valve body
harness connector and transaxle: Infinity
Is check results satisfactory? Intermittent trouble or
faulty TCM.
Check for intermittent
trouble referring to
“Intermittent and Poor
Connection Inspection
in Section 00”.
If OK, substitute a
known-good TCM and
recheck.
Replace TCC lock-up
pressure control
solenoid valve or lead
wire.
Step Action Yes No
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2Check TCC lock-up pressure control solenoid valve
resistance
1) Turn ignition switch OFF.
2) Disconnect valve body harness connector (1), (2) on
automatic transaxle.
3) Check for proper connection to solenoid at “WHT/BLU” and “WHT/BLK” circuits.
4) Check resistance of TCC lock-up pressure control
solenoid valve.
TCC lock-up pressure control solenoid valve
resistance
Between shift terminals of transaxle side valve body
harness connector: 5.0 – 5.6 Ω at 20 °C (68 °F)
Between shift terminals of transaxle side valve body
harness connector and transaxle: Infinity
Is check results satisfactory? Go to Step 3. Replace TCC lock-up
pressure control
solenoid valve or lead
wire.
3 Check TCC lock-up pressure control solenoid valve
circuit for ground short
1) Disconnect TCM connectors.
2) Check for proper connection to TCM at terminals “C34-
3” and “C34-5”.
3) If connection is OK, check continuity between terminal
“C34-5” of disconnected harness side TCM connector
and ground, between terminal “C34-3” of disconnected
harness side TCM connector and ground.
Are continuity indicated? “WHT/BLU” or “WHT/
BLK” circuit shorted to
ground.
Intermittent trouble or
faulty TCM.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
If OK, substitute a
known-good TCM and
recheck.
Step Action Yes No
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6
7
89
10 5
43 2
1
2
I4RS0A510020-01

Downloaded from www.Manualslib.com manuals search engine 5A-82 Automatic Transmission/Transaxle:
Inspection of TCM and Its CircuitsS7RS0B5104045
TCM and its circuits can be checked at TCM wiring connec tors by measuring voltage, pulse signal and resistance.
CAUTION!
TCM cannot be checked by itself, it is strictly prohibited to connect voltmeter or ohmmeter to TCM with
connector disconnected from it.

1) Remove TCM (1) from vehicle referring to “Transmission Control Module (TCM) Removal and Installation”.
2) Connect TCM connectors (2) to TCM.
3) Check voltage and/or pulse signal at each terminal of connectors connected using voltmeter (3) and oscilloscope
(4).
NOTE
• As each terminal voltage is affected by battery voltag e, confirm that it is 11 V or more when ignition
switch is ON.
• Voltage with asterisk(*) cannot be measured by voltmeter because it is pulse signal. Check it with oscilloscope if necessary.

Terminal arrangement of TCM coupler (Viewed from harness side)
5. Body ground
3
5 4
12
I6RS0C510009-01
65
16 15 14 13 12 11 43
24 23 2122 10 9 8 721
1920 18 17
C34
17 16
26 25
15 14
65 3
42
13 12
23 2224 11 10 9
21 20 19 87
18
1
C35
I4RS0A510022-01

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Troubleshooting
Brake Interlock System InspectionS7RS0B5104047
1) Check that select lever cannot be moved to any other range from “P” range position when ignition
switch key is at ACC position, at LOCK position or it
is removed from keyhole of ignition switch, or brake
pedal is not depressed. 2) Shift select lever to “P” range position, release knob
button and check for the following.
• Ignition key can be turned between LOCK and ACC positions back and forth and also it can be
removed from ignition switch.
Step Action Yes No
1 Check TCM back-up power circuit
1) Disconnect TCM connector with ignition switch OFF.
2) Check for proper connection to TCM at “C34-24”
terminal.
3) If OK, check voltage at terminal “C34-24” of disconnected TCM connector.
Is it 10 – 14 V? Go to Step 2. “WHT/RED” circuit open
or shorted to ground.
2 Check TCM power circuit
1) Disconnect TCM connector with ignition switch OFF.
2) Check for proper connection to TCM at “C34-6” terminal.
3) If OK, turn ignition switch ON and check voltage at
terminal “C34-6” of disconnected TCM connector.
Is it 10 – 14 V? Go to Step 4. Go to Step 3.
3 Check A/T relay operation
1) Check A/T relay operation referring to “A/T Relay
Inspection”.
Is check result satisfactory? “YEL/BLK”, “YEL/BLU”,
“LT GRN/BLK” or “BLK”
circuit for power supply
open.
Replace A/T relay.
4 Check TCM ground circuit
1) Turn ignition switch OFF.
2) With TCM connectors disconnected, check for proper
connection to TCM at “C34-1” / “C34-23” terminal.
3) If OK, check resistance between “C34-1” / “C34-23” terminal of disconnected TCM connector and body
ground.
Is continuity indicated? TCM power and ground
circuits are in good
condition.
“BLK” circuit for TCM
ground open.
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I4RS0A510048-01

Downloaded from www.Manualslib.com manuals search engine 5A-88 Automatic Transmission/Transaxle:
• With ignition switch turned to ACC position, push
shift lock solenoid release button (1). Then, select
lever can be shifted from “P” range position to any
other range.
• While ignition switch is at LOCK position, even when shift lock solenoid release button (1) is
pressed, select lever cannot be shifted from P
range position to any other range.
• When ignition switch is turned ON and brake pedal is depressed, select lever can be shifted
from “P” range position to any other range. 3) With select lever shifted to any position other than
“P” range, check that ignition key cannot be turned
LOCK position and it cannot be removed from
ignition switch unless it is at LOCK position.
Repair Instructions
Learning Control InitializationS7RS0B5106001
1) Connect san tool to DLC (1) with ignition switch OFF.
Special tool
(A): SUZUKI scan tool
2) Start engine and shift select lever to “P” range.
3) Select “Misc Test” mode on scan tool.
4) Perform “AT learned initialize” on scan tool.
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(A)I4RS0B510004-01

Downloaded from www.Manualslib.com manuals search engine Automatic Transmission/Transaxle: 5A-91
Select Lever InspectionS7RS0B5106007
Check select lever for smooth and clear-cut movement
individually. If a malfunction is found, replace select lever
assembly.
“3” Position Switch InspectionS7RS0B5106008
1) Remove console box referring to “Console Box Components in Section 9H”.
2) Disconnect “3” position switch connector (1).
3) Check continuity between “3” position switch terminals.
“3” position switch specification
Shift select lever to “3 ” or “2” range: Continuity
Shift other above range: No continuity
Shift Lock Solenoid InspectionS7RS0B5106009
Check that shift lock soleno id rod (1) moves smoothly
when battery voltage is conducted and it moves back. If
solenoid rod does not move smoothly, replace.
Shift Lock Solenoid ReplacementS7RS0B5106010
1) Remove console box referring to “Console Box Components in Section 9H”.
2) Replace shift lock solenoid (1) using flat head or like.
3) Install covers as they were.
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