1999 MITSUBISHI LANCER EVOLUTION VI check engine

MPI – Troubleshooting13-6
TROUBLESHOOTING
DIAGNOSIS TROUBLESHOOTING FLOW
Refer to GROUP 00 – How to Use Troubleshooting/Inspection
Service Points.
DIAGNOSIS FUNCTION
ENGINE WARNING LAMP (CHECK ENGINE LAMP)
If an abnormality occurs in any of the following items related
to the Multipoint Fuel Injection (MPI) system, the engine
warning lamp will illuminate.
If the lamp remains illuminated or if the lamp illuminates while
the engine is running, check the diagnosis code output.
Engine warning lamp inspection items
Engine-ECU
Air flow sensor
Intake air temperature sensor
Throttle position sensor
Engine coolant temperature sensor
Crank angle sensor
Camshaft position sensor
Barometric pressure sensor
Detonation sensor
Injector
Ignition coil, power transister unit
METHOD OF READING AND ERASING DIAGNOSIS
CODES
Refer to GROUP 00 – How to Use Troubleshooting/Inspection
Service Points.
INSPECTION USING MUT-II DATA LIST AND
ACTUATOR TESTING
1. Carry out inspection by connecting the MUT-II.
If there is an abnormality, check and repair the chassis
harnesses and components.
2. After repairing, check that the abnormal input and output
have returned to normal as a result of the repairs.
3. Erase the diagnosis code memory.
4. Remove the MUT-II and carry out a road test to confirm
that the problem has disappeared.
Engine warning lamp
(check engine lamp)

MPI – Troubleshooting13-8
3. INSPECTION CHART FOR DIAGNOSIS CODES
Code No.Diagnosis itemReference page
12Air flow sensor system13-8
13Intake air temperature sensor system13-9
14Throttle position sensor system13-9
21Engine coolant temperature sensor system13-10
22Crank angle sensor system13-11
23Camshaft position sensor system13-12
24Vehicle speed sensor system13-13
25Barometric pressure sensor system13-14
31Detonation sensor system13-15
41Injector system13-15
44Ignition coil and power transistor unit system13-16
64Alternator FR terminal system13-17
INSPECTION PROCEDURE FOR DIAGNOSIS CODES
Code No. 12 Air flow sensor systemProbable cause
Range of Check

Engine speed is 500 r/min or more.
Set conditions

Sensor output frequency is 3 Hz or less for 4 seconds.
Malfunction of the air flow sensor

Improper connector contact, open or short-circuited
harness wire of the air flow sensor

Malfunction of the engine-ECU
Measure at the air flow sensor con-
nector A-25.

Connect the connector. (Use
the test harness: MB991709)
1. Voltage between 3 and earth
(Engine: Idling)
OK:2.2–3.2 V
2. Voltage between 7 and earth
OK:0–1 V (Engine: idling)
6–9 V (2,000 r/min)
OK
Replace the engine-ECU.1. NG
Check the air flow sensor circuit.
(Refer to P.13-55, INSPECTION
PROCEDURE 48.)
2. NG
Measure at the engine-ECU con-
nector B-59.

Connect the connector.

Voltage between 19 and earth
(Ignition switch: ON)
OK:6–9 V
OK
Check the following connector:
B-59
OK
Check trouble symptom.
NG
Replace the engine-ECU.NG
Check the following connector:
A-25NG
Repair
OK
Check trouble symptom.
NG
NG
Repair
Replace the air flow sensor.

MPI – Troubleshooting13-9
Code No. 13 Intake air temperature sensor systemProbable cause
Range of Check

Ignition switch: ON

Excluding 60 seconds after the ignition switch is turned to ON or immediately
after the engine starts.
Set conditions

Sensor output voltage is 4.6 V or more (corresponding to an intake air temperature
of –45C or less) for 4 seconds.
or

Sensor output voltage is 0.2V or less (corresponding to an intake air temperature
of 125C or more) for 4 seconds.
Malfunction of the intake air temperature sensor

Improper connector contact, open or short-circuited
harness wire of the intake air temperature sensor circuit

Malfunction of the engine-ECU
Check the intake air temperature
sensor. (Refer to P.13-32.)*NG
OK
Measure at the air flow sensor con-
nector A-25.

Disconnect the connector, and
measure at the harness side.

Voltage between 6 and earth
(Ignition switch: ON)
OK:4.5–4.9 V

Continuity between 5 and earth
OK:ContinuityNGCheck the following connector:
B-62NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between
the engine-ECU and the intake air
temperature sensor connector.NG
Repair
OK
Replace the engine-ECU. OK
Check the following connector:
A-25NG
Repair
OK
Check trouble symptom.NGReplace the engine-ECU.
Replace the air flow sensor.
NOTE
*: Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).
Code No. 14 Throttle position sensor system
Probable cause
Range of Check

Ignition switch: ON

Excluding 60 seconds after the ignition switch is turned to ON or immediately
after the engine starts.
Set conditions

The sensor output voltage is 0.2 V or less for 4 seconds.
Malfunction of the throttle position sensor

Improper connector contact, open or short-circuited
harness wire of the throttle position sensor circuit

Improper “ON” state of idle position switch

Short circuit of the idle position switch signal line

Malfunction of the engine-ECU
MUT-II Data list
26 Idle position switch system
OK:With the throttle valve at the
idle position: ON
With the throttle valve slight-
ly open: OFFNGCheck the idle position switch system.
(Refer to P.13-38, INSPECTION PRO-
CEDURE 26.)
OK
Check the throttle position sensor.NG
Replace
OK
Measure at the throttle position sensor
connector A-16.

Disconnect the connector, and
measure at the harness side.

Voltage between 1 and earth
(Ignition switch: ON)
OK:4.8–5.2 V

Continuity between 4 and earth
OK:ContinuityNGCheck the following connector:
B-62NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between the
engine-ECU and the throttle position
sensor connector.NG
Repair
OK
Replace the engine-ECU. OK
Check the throttle position sensor out-
put circuit. (Refer to P.13-55, INSPEC-
TION PROCEDURE 49.)

MPI – Troubleshooting13-10
Code No. 21 Engine coolant temperature sensor systemProbable cause
Range of Check

Ignition switch: ON

Excluding 60 seconds after the ignition switch is turned to ON or immediately
after the engine starts.
Set conditions

Sensor output voltage is 4.6 V or more (corresponding to an engine coolant
temperature of –45C or less) for 4 seconds.
or

Sensor output voltage is 0.1 V or less (corresponding to an engine coolant
temperature of 140C or more) for 4 seconds.
Malfunction of the engine coolant temperature sensor

Improper connector contact, open or short-circuited
harness wire of the engine coolant temperature sensor
circuit

Malfunction of the engine-ECU
Range of Check

Ignition switch: ON

Engine speed is approx. 50 r/min or more
Set conditions

The sensor output voltage increases from 1.6 V or less (corresponding to an
engine coolant temperature of 40C or more) to 1.6 V or more (corresponding
to an engine coolant temperature of 40C or less).

After this, the sensor output voltage is 1.6 V or more for 5 minutes.
Check the engine coolant temperature
sensor. (Refer to P.13-32.)*NG
Replace
OK
Measure at the engine coolant temper-
ature sensor connector A-38.

Disconnect the connector, and
measure at the harness side.

Voltage between 1 and earth
(Ignition switch: ON)
OK:4.5–4.9 V

Continuity between 2 and earth
OK:ContinuityNGCheck the following connector:
B-62NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between the
engine-ECU and the engine coolant
temperature sensor connector.NG
Repair
OK
Replace the engine-ECU.
Check the following connector:
A-38OKCheck trouble symptom.
NG
Replace the engine-ECU.
NG
RepairOK
NOTE
*: Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).

MPI – Troubleshooting13-11
Code No. 22 Crank angle sensor systemProbable cause
Range of Check

Engine is cranking.
Set conditions

Sensor output voltage does not change for 4 seconds (no pulse signal input.)
Malfunction of the crank angle sensor

Improper connector contact, open or short-circuited
harness wire of the crank angle sensor

Malfunction of the engine-ECU
Measure at the crank angle sensor connector A-51.

Connect the connector. (Use the test harness: MD998478.)

Voltage between 2 (black clip) and earth (Engine: cranking)
OK:0.4–4.0 V

Voltage between 2 (black clip) and earth (Engine: idling)
OK:1.5–2.5 V
NGOKReplace the engine-ECU.
Measure at the crank angle sensor connector A-51.

Disconnect the connector, and measure at the harness side.
1. Voltage between 3 and earth (Ignition switch: ON)
OK:System voltage
2. Voltage between 2 and earth (Ignition switch: ON)
OK:4.8–5.2 V
3. Continuity between 1 and earth
OK:Continuity
OK
Check the following con-
nector: A-51NG
Repair
OK
Check trouble symptom.
NG
Replace the crank angle sensor.1. NG
Check the harness wire between the crank angle sensor and the
control relay connector, and repair if necessary.
2. NGCheck the following con-
nector: B-62NG
Repair
OK3. NG
Check trouble symptom.
NG
Check the harness wire
between the engine-ECU
and the crank angle sensor
connector.NG
Repair
OK
Replace the engine-ECU.
Check the harness wire between the crank angle sensor and the
earth, and repair if necessary.

MPI – Troubleshooting13-12
Code No. 23 Camshaft position sensor systemProbable cause
Range of Check

Ignition switch: ON

Engine speed is approx. 50 r/min or more.
Set conditions

Sensor output voltage does not change for 4 seconds (no pulse signal input.)
Malfunction of the camshaft position sensor

Improper connector contact, open or short-circuited
harness wire of the camshaft position sensor circuit

Malfunction of the engine-ECU
Measure at the camshaft position sensor connector A-97.

Connect the connector.

Voltage between 2 and earth (Engine: cranking)
OK:0.4–3.0 V

Voltage between 2 and earth (Engine: idling)
OK:0.5–2.0 VOKReplace the engine-ECU.
NG
Measure at the camshaft position sensor connector A-97.

Disconnect the connector, and measure at the harness side.
1. Voltage between 3 and earth (Ignition switch: ON)
OK:System voltage
2. Voltage between 2 and earth (Ignition switch: ON)
OK:4.8–5.2 V
3. Continuity between 1 and earth
OK:Continuity1. NGCheck the harness wire between the camshaft position sensor
and the control relay connector, and repair if necessary.
2. NGCheck the following con-
nector: B-62NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire
between the engine-ECU
and the camshaft position
sensor connector.NG
Repair
OK
Replace the engine-ECU. 3. NG
Check the harness wire between the camshaft position sensor
and the earth, and repair if necessary.
OK
Check the following con-
nector: A-97NG
Repair
OK
Check trouble symptom.
NG
Replace the camshaft position sensor.

MPI – Troubleshooting13-13
Code No. 24 Vehicles speed sensor systemProbable cause
Range of check

Ignition switch: ON

Excluding 60 seconds after the ignition switch is turned to ON or immediately
after the engine starts.

Idle position switch: OFF

Engine speed is 3,000 r/min or more.

Driving under high engine load conditions.
Set conditions

Sensor output voltage does not change for 4 seconds (no pulse signal input).
Malfunction of the vehicle speed sensor

Improper connector contact, open or short-circuited
harness wire of the vehicle speed sensor circuit

Malfunction of the engine-ECU
OK
Check the ignition switch. (Refer to GROUP 54 – Ignition Switch.)
2. NG
OK
Replace the engine-ECU.
3. NG
OK
Replace the engine-ECU.
NG
Check the harness wire
between the engine-ECU
and the vehicle speed
sensor connector.NG
Repair
OK
Check trouble symptom.
OK
Check the following
connectors:
A-19, B-62NG
Repair
NG
Check the harness wire
between the engine-ECU
and the vehicle speed
sensor connector.NG
Repair
OK
Check trouble symptom.
Check the following
connector: B-62NG
Repair
NG
Check the harness wire
between the vehicle
speed sensor and ignition
switch connector.NG
Repair
OK
Check trouble symptom.
OK
Measure at the vehicle speed sensor connector A-19.

Disconnect the connector, and measure at the harness
side.
1. Voltage between 1 and earth (Ignition switch: ON)
OK:System voltage
2. Voltage between 3 and earth (Ignition switch: ON)
OK:4.8 – 5.2 V
3. Continuity between 2 and earth
OK:Continuity1. NGCheck the following
connectors:
B-64, B-74, B-76NG
Repair
Check the vehicle speed sensor. (Refer to GROUP 54 – Combina-
tion Meters.)NG
Replace
Check the harness wire between the vehicle speed sensor and
the earth, and repair if necessary.

MPI – Troubleshooting13-14
Code No. 25 Barometric pressure sensor systemProbable cause
Range of Check

Ignition switch: ON

Excluding 60 seconds after the ignition switch is turned to ON or immediately
after the engine starts.
Set conditions

Sensor output voltage is 4.5 V or more (corresponding to a barometric pressure
of 114 kPa or more) for 4 seconds.
or

Sensor output voltage is 0.2 V or less (corresponding to a barometric pressure
of 5.33 kPa or less) for 4 seconds.
Malfunction of the barometric pressure sensor

Improper connector contact, open or short-circuited
harness wire of the barometric pressure sensor circuit

Malfunction of the engine-ECU
Measure at the air flow sensor con-
nector A-25.

Connect the connector. (Use
the test harness: MB991709)

Voltage between 2 and earth
(Ignition switch: ON)
OK:3.7–4.3 V (Altitude: 0 m)
3.2–3.8V (Altitude:
1,200 m)NGMeasure at the air flow sensor con-
nector A-25.

Disconnect the connector, and
measure at the harness side.

Voltage between 1 and earth
(Ignition switch: ON)
OK:4.8–5.2 V

Continuity between 5 and earth
OK:ContinuityNGCheck the following connector:
B-62NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between
the engine-ECU and the baromet-
ric pressure sensor connector.NG
Repair
OK
Replace the engine-ECU.
OK
Check the following connector:
A-25NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between
the engine-ECU and the baromet-
ric pressure sensor connector.NG
Repair
OK
Replace the air flow sensor.
OK
Measure at the engine-ECU con-
nector B-62.

Connect the connector.

Voltage between 85 and earth
(Ignition switch: ON)
OK:3.7–4.3 V (Altitude: 0 m)
3.2–3.8V (Altitude:
1,200 m)NGCheck the harness wire between
the engine-ECU and the baromet-
ric pressure sensor connector, and
repair if necessary.
Check the following connector:
A-25, B-62
OK
Check trouble symptom.
NG
Replace the engine-ECU.NG
Repair OK