
SYSTEM Ð ENGINE CONTROL system
Malfunction
SYMPTOM
Reference page
Feature of symptom, Check pointROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEAT/HIGH ENGINE COOLANT TEMPERATURE
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
ABNORMAL SMOKE COLOR
DEAD BATTERY (UNDER CHARGE)
Malfunction indicator lamp illuminates.
Can be detected by CONSULT-II?
Fuel cutBLACK SMOKE
WHITE SMOKEWarranty symptom code AG AH AJ AK AL AM AP HA
ENGINE CONTROL
Start signal circuit *a, *b EC-248 *3
PNP switch circuit*a, *b
1 1 EC-251
*c
Accelerator position switch (Idle) cir-
cuit*a, *c
EC-130
*b 1 1 *4
Accelerator position switch (Full) cir-
cuit*a, *b 1 1 EC-130
Ignition switch circuit*a
EC-79
*b*5
Power supply for ECM circuit*a
111
EC-79
*b
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*a: Open
*b: Short
*c: Ground short
*d: Noise
*3: Start control does not function.
*4: Accelerator position sensor NG signal is output.
*5: Engine does not stop.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
Symptom Matrix Chart (Cont'd)
EC-63

Description
The stop lamp switch is installed to brake pedal bracket. The switch
senses brake pedal position and sends an ON-OFF signal to the
ECM. The ECM uses the signal to control the fuel injection control
system.
ECM Terminals and Reference Value
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may damage the
ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
17 G/Y Stop lamp switchIgnition switch ªONº
Brake pedal fully releasedApproximately 0V
Ignition switch ªONº
Brake pedal depressedBATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis Logic
Malfunction is detected when ... Check Items (Possible Cause)
IAn irregular voltage signal from the switch is sent to ECM.IHarness or connectors
(The stop lamp switch circuit is open or shorted.)
IStop lamp switch
DTC Confirmation Procedure
WITH CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Depress and release brake pedal more than 10 times.
4) If DTC is detected, go to ªDiagnostic Procedureº, EC-206.
WITHOUT CONSULT-II
1) Turn ignition switch ªONº.
2) Depress and release brake pedal more than 10 times.
3) Turn ignition switch ªOFFº, wait at least 5 seconds and then turn
ªONº.
4) Perform ªDiagnostic Test Mode II (Self-diagnostic results)º with
ECM.
5) If DTC is detected, go to ªDiagnostic Procedureº, EC-206.
MEC027E
SEF817Y
DTC 0807 ECM 14ZD30DDTi
EC-204

Component Description
The heat up switch is located on the lower side of the instrument
panel. This switch is used to speed up the heater's operation when
the engine is cold.
When the ECM received the heat up switch ªONº signal, the ECM
increases the engine idle speed to 1,100 to 1,200 rpm to warm up
engine quickly.
This system works when all conditions listed below are met.
Heat up switch ON
Engine coolant temperature Below 105ÉC (221ÉF)
Shift lever ªPº or ªNº
Accelerator pedal Fully released
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
WARM UP SWIIgnition switch: ONHeat up switch: ON ON
Heat up switch: OFF OFF
ECM Terminals and Reference Value
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may damage the
ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIOND ATA
(DC Voltage and Pulse
Signal)
59 G Heat up switchIgnition switch ªONº
Heat up switch is ªOFFº.0V
Ignition switch ªONº
Heat up switch is ªONº.BATTERY VOLTAGE
(11 - 14V)
HEAT UP SWITCHZD30DDTi
EC-258

Air Conditioning Cut Control
INPUT/OUTPUT SIGNAL LINE
Air conditioner switchEAir Conditioner ªONº signal
ECM
EAir Condi-
tioner relay
Accelerator position sensorEAccelerator valve opening angle
Vehicle speed sensor
EVehicle speed
Engine coolant temperature sensor
EEngine coolant temperature
SYSTEM DESCRIPTION
This system improves acceleration when the air conditioner is used.
When the accelerator pedal is fully depressed, the air conditioner is turned off for a few seconds. When engine
coolant temperature becomes excessively high, the air conditioner is turned off. This continues until the cool-
ant temperature returns to normal.
Fuel Cut Control (at high engine speed)
INPUT/OUTPUT SIGNAL LINE
Crankshaft position sensor (TDC)EEngine speed
ECMEElectric
governor
If the engine speed is above 5,500 rpm fuel will be cut off to keep
engine within its working range.
NOTE:
This function is different from deceleration control and fuel cut
solenoid valve control.
Glow Control
INPUT/OUTPUT SIGNAL LINE
Engine coolant temperature sensorEEngine coolant temperature
ECMEGlow relayEGlow plug
Ignition switchEStart signalEGlow lamp
Glow plug is heated in three-stage that is pre-glow, intermediate-
glow and after-glow. Glow time changes depending on engine cool-
ant temperature.
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTIONTD27Ti
EC-311

System Description
EGR CONTROL
Camshaft position sensor (TDC)EEngine speed
ECMEEGRC-solenoid valve A
Mass air flow sensorEMass air flowEEGRC-solenoid valve B
Engine coolant temperature sensorEEngine coolant temperatureEThrottle control solenoid valve
Ignition switchEStart signal
Atmospheric pressure sensor
EAtmospheric pressure
Air conditioner switch
EAir conditioner ªONº signal
The ECM receives signals sent from the engine coolant tempera-
ture sensor, crankshaft position sensor (TDC), ignition switch etc.
to determine engine speed and operating conditions. Based on
these signals, the ECM controls EGRC-solenoid valve (A and B)
operation and throttle solenoid valve operation.
The EGR control stops when engine coolant temperature is below
45ÉC (113ÉF), at idling, at starting and when the system compo-
nents and engine speed signals are disordered.
Engine coolant
temperature
ÉC (ÉF)LoadEGRC-solenoid valve
Throttle control
solenoid valveEGR valveThrottle control
valveAmount of EGR
gas
AB
Below 45 (113) AnyOFF
(Closed)OFF
(Closed)OFF
(Closed)Fully closed Fully open Ð
Above 45 (113)Low loadON
(Open)ON
(Open)ON
(Open)Fully open Closed Large
Medium load-1ON
(Open)ON
(Open)OFF
(Closed)Fully open Fully open Medium
Medium load-2ON
(Open)OFF
(Closed)OFF
(Closed)Half open Fully open Small
High loadOFF
(Closed)OFF
(Closed)OFF
(Closed)Fully closed Fully open Ð
Component Description
The EGRC-solenoid valves A and B, control vacuum pressure act-
ing on the EGR valve. The EGR control valve will be fully opened,
half-opened or fully closed, as required.
The throttle control solenoid valve controls vacuum pressure acting
on the throttle control valve. Thus, intake air passages are opened
or closed in relation to exhaust gas and intake air. Utilizing the
relationship between exhaust gas pressure and intake air pressure
control, the amount of EGR (exhaust gas recirculated) is regulated
in three approximate measures Ð large, medium, small.
NEF513
DTC P1404 EGR SOL/V A, DTC P1405 EGR SOL/V B/P1407
THROTTLE SOLENOID VALVETD27Ti
EC-431

System Description
Refer to Owner's Manual for audio system operating instructions.
NATS AUDIO LINK
Description
The link with the NATS IMMU implies that the audio unit can basically only be operated if connected to the
matching NATS IMMU to which the audio unit was initially fitted on the production line.
Since radio operation is impossible after the link with the NATS is disrupted theft of the audio unit is basically
useless since special equipment is required to reset the audio unit.
Initialization process for audio units that are linked to the NATS IMMU
New audio units will be delivered to the factories in the ªNEWº state, i.e. ready to be linked with the vehicle's
NATS. When the audio unit in ªNEWº state is first switched on at the factory, it will start up communication
with the vehicle's immobiliser control unit (IMMU) and send a code (the ªaudio unit Codeº) to the IMMU. The
IMMU will then store this code, which is unique to each audio unit, in its (permanent) memory.
Upon receipt of the code by the IMMU, the NATS will confirm correct receipt of the audio unit code to the audio
unit. Hereafter, the audio unit will operate as normal.
During the initialisation process, ªNEWº is displayed on the audio unit display. Normally though, communica-
tion between audio unit and IMMU takes such a short time that the audio unit seems to switch on directly
without showing ªNEWº on its display.
Normal operation
Each time the audio unit is switched on afterwards, the audio unit code will be verified between the audio unit
and the NATS before the audio unit becomes operational. During the code verification process, ªWAITº is
shown on the audio unit display. Again, the communication takes such a short time that the audio unit seems
to switch on directly without showing ªWAITº on its display.
When the radio is locked
In case of a audio unit being linked with the vehicle's NATS (immobilizer system), disconnection of the link
between the audio unit and the IMMU will cause the audio unit to switch into the lock (ªSECUREº) mode in
which the audio unit is fully inoperative. Hence, repair of the audio unit is basically impossible, unless the audio
unit is reset to the ªNEWº state for which special decoding equipment is required.
Clarion has provided their authorized service representatives with so called ªdecoder boxesº which can bring
the audio unit back to the ªNEWº state, enabling the audio unit to be switched on after which repair can be
carried out. Subsequently, when the repaired audio unit is delivered to the final user again, it will be in the
ªNEWº state as to enable re-linking the audio unit to the vehicle's immobiliser system. As a result of the above,
repair of the audio unit can only be done by an authorized Clarion representative.
Service instruction
Item Radio linked with IMMU and/or SECU
Battery disconnection No additional action required
Radio needs repair Repair needs to be done by authorised representative of radio manufacturer since radio
cannot be operated unless it is reset to NEW state, using special decoding equipment
Replacement of radio by new part Radio is delivered in NEW state. If possible, the radio will automatically link up with the
immobiliser system. If this appears not possible, CATS code needs to be manually input
Transferring radio to another vehicle /
replacement of radio by an ªoldº partRadio needs to be reset to NEW state by authorised representative of radio manufac-
turer
Replacement of IMMU by new part Radio will request for CATS code input prior to establishing the link with the IMMU
Replacement of IMMU by old part If a radio code has already been stored in memory of the IMMU, the radio cannot be
linked to it. After switching on the radio, it will display ªSECUREº after 1 minute. Opera-
tion can only be established after resetting the ratio by an authorised representative of
radio manufacturer
CATS code input procedure
1. Radio displays ªCODE INº after the power is switched ON.
2. Enter CATS code (4-digits) by pressing the preset buttons (using 1 to 4).
Press the preset buttons for the necessary amount of times for the number of each digits.
e.g. CATS code is ª5432º
Press No. 1 preset button for 5 times
Press No. 2 preset button for 4 times
AUDIO
EL-111

Trouble Diagnosis
The Timer Control Unit includes software to help during development testing, manufacturing and service.
It allows the technician to put it into Diagnostic Mode. In this mode, all switch inputs can be tested for conti-
nuity and if so equipped, alarm triggers identified.
When the time control unit is in Diagnostic Mode, the control unit tests the component and indicate the result
by the hazard lamp flashing.
On vehicles with a theft warning system, the TCU will first indicate the source of the last three alarm triggers
by flashing the hazard lamp. (Refer to ªTHEFT WARNING SYSTEMº, EL-209.)
ESTART
NOTE: Before entering diagnostic mode, make sure the vehicle is fully unlocked,
the ignition is switched off and the hazard switch is off.
Press the rear defogger switch exactly 6 times within 10 seconds.
FNG
The hazard lamp flash at 3 Hz for 1 second to confirm step I.
OK
Within 10 seconds after confirmation of step I, turn the ignition ON, for at least 2 seconds.
FNG
The hazard lamp flash at 3 Hz for 1 second to confirm step II.
OK
Within 10 seconds after confirmation of step II, turn the ignition off,
remove the ignition key and press the rear defogger switch for at least 5 seconds.
NGThe hazard lamp flash at 3 Hz for 3 seconds to confirm diagnostic mode is entered.
H
H
H
H
H
H
TIME CONTROL UNIT (TCU)
EL-182

Trouble Diagnoses
Alarm Trigger Feedback
To verify the last three triggers that activated the theft warning system, the Time Control Unit (TCU) can be
switched into Diagnostic Mode (see page EL-182 how to enter Diagnostic Mode).
Approximately 2 seconds after the TCU has finished flashing the hazard lamp to confirm that the Diagnostic
Mode has been successfully entered, the TCU will generate a short beep indicating the trigger that will be dis-
played. A single beep means the most recent trigger, three beeps means the oldest trigger. Following each
beep or group of beeps, the hazard lamp will flash to indicate the alarm trigger.
Source of Alarm Trigger Number (of flashes)
Driver's door lock status switch 1
Passenger door lock status switch 2
Rear door lock status switch 3
Ignition line 4
Driver's door open switch 5
Other door open switch 6
Trunk or back door open switch 8
Hood switch 9
Ultrasonic sensors 10
In case there have been no alarm triggers, there will be no indicator flashes between the audible signals. After
completing the alarm trigger feedback, the TCU will enter Diagnostic Mode as described on page EL-182.
Before continuing trouble diagnoses on the next page, perform the checks as mentioned in the table on page
EL-183.
THEFT WARNING SYSTEM
EL-230