1998 MITSUBISHI MONTERO engine

L - WIRING DIAGRAMS article.
1) Specific self-diagnostic test is not available from
manufacturer at time of publication. Check ignition coil, power
transistor, spark plugs, fuel injectors, heated oxygen sensor,
crankshaft position sensor, and related connectors and harnesses.
2) Also check compression pressure, timing belt, fuel
pressure, and for intake air leaks. See F - BASIC TESTING article.
DTC P0325: KNOCK SENSOR (KS) NO. 1 CIRCUIT FAILURE
NOTE: This test applies to 3000GT equipped with DOHC engine only.
For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Component or scan tool testing procedure not available
from manufacturer at time of publication. Turn ignition switch to OFF
position. Disconnect KS connector and PCM connector. Ground PCM
connector terminal No. 91. Go to next step.
2) Using DVOM, check for continuity between chassis ground
and KS connector terminal No. 1. If continuity does not exist, repair
wiring harness as necessary. If continuity exists, go to next step.
3) Remove jumper wire from PCM connector terminal No. 1.
Check for continuity between chassis ground and KS connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
4) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P0335: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
NOTE: Procedures are provided by manufacturer for component
testing using an engine analyzer with oscilloscope
capability. Refer to manufacturer's operation manual for
instructions in use of oscilloscope.
1) If using scan tool, go to step 3). Disconnect CKP sensor
connector. Install Test Harness (MB991348) between CKP sensor and
connector. Using engine analyzer with oscilloscope capability, connect
special patterns probe to CKP sensor connector terminal No. 2. Go to
next step.
2) Start engine. Compare oscilloscope wave pattern with
known-good wave pattern. See Fig. 38. Verify wavelength (time)
decreases as engine RPM increases. If wave pattern fluctuates to left
or right, check for loose timing belt or an abnormality in sensor
pick-up disc. If a rectangular wave pattern is generated even when
engine is not started, substitute known-good CKP sensor. Repeat test.
If wave pattern is still abnormal, go to step 6).
Fig. 38: Identifying Known-Good CKP Sensor Wave Pattern
Courtesy of Mitsubishi Motor Sales of America

3) Connect an engine tachometer. Crank engine. Ensure
ignition coil primary current toggles on and off. Using scan tool,
read engine cranking speed (item 22). Compare tachometer and scan tool\
RPM display. Go to next step.
4) If engine fails to start and tachometer reads zero RPM
when engine is cranked, check for broken timing belt or faulty CKP
sensor. If CKP sensor is suspected, substitute known-good CKP sensor.
Repeat test procedure. If engine fails to start, tachometer reads zero
RPM, and ignition coil primary current fails to toggle on and off,
check for faulty ignition coil, ignition circuit or power transistor.
If engine starts and readouts agree, go to next step.
5) Ensure A/C switch is in ON position to activate closed
throttle position switch. Allow engine to idle. Using scan tool, check
engine coolant temperature and read idle speed. See
IDLE RPM SPECIFICATIONS table. If RPM is not to specification, check
for faulty ECT sensor, basic idle speed adjustment, or idle air
control motor. If RPM is within specifications, go to next step.
IDLE RPM SPECIFICATIONS TABLE









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Engine Coolant Temperature Engine RPM
-4
F (-20C)
Montero ...................................... 1300-1500
3000GT
Non-Turbo .................................. 1275-1475
Turbo ...................................... 1300-1500
32
F (0C)
Montero ...................................... 1300-1500
3000GT
Non-Turbo .................................. 1225-1425
Turbo ...................................... 1300-1500
68
F (20C)
Montero ...................................... 1300-1500
3000GT
Non-Turbo .................................. 1100-1300
Turbo ...................................... 1300-1500
104
F (40C)
Montero ...................................... 1040-1240
3000GT
Non-Turbo ................................... 950-1150
Turbo ...................................... 1050-1250
176
F (80C)
Montero & 3000GT ............................... 600-800









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6) On 3000GT, go to next step. On Montero, disconnect CKP
sensor connector and MFI relay connector. Using DVOM, check for
continuity between CKP sensor connector terminal No. 3 and MFI relay
connector terminal No. 1. If continuity does not exist, repair wiring
harness as necessary. If continuity exists, go to next step.
7) With CKP sensor connector disconnected, check for
continuity between chassis ground and CKP sensor connector terminal
No. 1 on Montero or No. 2 on 3000GT. If continuity does not exist,
repair wiring harness as necessary. If continuity exists on 3000GT, go
to next step. On Montero, go to step 9).
8) Check for voltage between chassis ground and CKP sensor
connector terminal No. 3. If battery voltage does not exist, repair
wiring harness as necessary. If battery voltage exists, go to step
10).
9) Turn ignition switch to OFF position. With CKP sensor
connector disconnected, disconnect PCM connector. Check for continuity

between CKP sensor connector terminal No. 2 and PCM connector terminal
No. 43. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
10) With ignition switch in ON position, check for voltage
between chassis ground and CKP sensor connector terminal No. 2. If 4.
8-5.2 volts do not exist, replace PCM. If voltage is to specification
and CKP sensor is suspected, go to next step.
11) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P0340: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
NOTE: Procedures are provided by manufacturer for component
testing using an engine analyzer with oscilloscope
capability. Refer to manufacturer's operation manual for
instructions in use of oscilloscope.
1) If using scan tool, go to step 3). Disconnect CMP sensor
connector. Install Test Harness (MB991348) between CMP sensor and
connector. Using engine analyzer with oscilloscope capability, connect
special patterns probe to CMP sensor connector terminal No. 2. Go to
next step.
2) Start engine. Compare oscilloscope wave pattern with
known-good wave pattern. See Fig. 39. Verify wavelength (time)
decreases as engine RPM increases. If wave pattern fluctuates to left
or right, check for loose timing belt or an abnormality in sensor
pick-up disc. If a rectangular wave pattern is generated even when
engine is not started, substitute known-good CMP sensor. Repeat test.
If wave pattern is still abnormal, go to next step.
Fig. 39: Identifying Known-Good CMP Sensor Wave Pattern
Courtesy of Mitsubishi Motor Sales of America
3) On Montero, go to next step. On 3000GT, disconnect CMP
sensor connector. Turn ignition switch to ON position. Check voltage
between chassis ground and CMP sensor connector terminal No. 3. If
battery voltage does not exist, repair wiring harness as necessary. If
battery voltage exists, go to step 5).
4) Disconnect CMP sensor connector and MFI relay connector.
Using DVOM, check for continuity between CMP sensor connector terminal
No. 3 and MFI relay connector terminal No. 1. If continuity does not
exist, repair wiring harness as necessary. If continuity exists, go to
next step.
5) Check for continuity between chassis ground and CMP sensor
connector terminal No. 4 on 3000GT equipped with DOHC engine or 1 on

continuity between chassis ground and EGR solenoid connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, condition required to set DTC is not
present at this time. Go to next step.
12) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P0420, P0421 & P0431: CATALYST EFFICIENCY BELOW
THRESHOLD
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
Specific self-diagnostic test not available from manufacturer
at time of publication. Check catalytic converter and check for
cracked exhaust manifold. Also, see F - BASIC TESTING article.
DTC P0442: EVAPORATIVE (EVAP) EMISSION CONTROL SYSTEM LEAK
DETECTED
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Remove fuel cap. Push fuel pipe restrictor to operate On-
board Fuel Vent Valve (OFLV). Install and tighten fuel cap. Remove
fuel cap and ensure distance between filler tube and OFLV is 1.1" (28
mm). If distance is as specified, go to next step. If distance is not
as specified, replace fuel tank filler tube assembly. Go to step 24).
2) Disconnect and plug air filter-to-EVAP vent solenoid hose
at air filter. Disconnect intake manifold plenum-to-EVAP purge
solenoid at intake manifold plenum. Install a "T" fitting between
vacuum hose and intake manifold plenum. Connect a hand-held
pressure/vacuum pump to "T" fitting. Go to next step.
CAUTION: DO NOT apply more than 0.57 psi in following step. Applying
more than specified psi can crack fuel tank.
NOTE: Ensure fuel tank is at least 1/4 full. The lower the fuel
level in fuel tank, the longer it takes to pressurize fuel
system.
3) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, apply\
0.42 psi. If scan tool reading reaches 0.42 psi, go to next step. If
reading does not reach 0.42 psi, go to step 9).
4) Wait 20 seconds and read scan tool. If scan tool reading
increases 0.06 psi or less, go to next step. If scan tool reading
increases more than 0.06 psi, go to step 21).
5) Disconnect EVAP canister purge hose. Connect Purge Flow
Indicator (MB995061) between EVAP canister and disconnected hose. Turn\
engine on and allow it to reach operating temperature. Turn all lights
and accessories off. Place transmission in Park or Neutral. Observe
purge flow indicator while increasing engine RPM several times. If
purge flow indicator reads less than 2.5 SCFH (20 cm(3)/sec), check
EVAP canister purge hose and EVAP canister port for clogging. If hose
and port are okay, check EVAP purge solenoid. See DTC P0443. If
solenoid is okay, replace EVAP canister. Go to step 24).
6) Using scan tool, read Engine Coolant Temperature (ECT)
sensor temperature (item 21). Compare scan tool reading with

temperature gauge reading. If readings are about the same, go to next
step. If readings are not about the same, go to DTC P0115 test.
7) Using a thermometer, check engine compartment ambient
temperature. Using scan tool, read Intake Air Temperature (IAT) sensor\
temperature (item 13). Compare IAT sensor and thermometer readings. If\
readings are not about the same, go to DTC P0110 test. If readings are
about the same, go to next step.
8) Using scan tool, read Power Steering Pressure (PSP) switc\
h
status (item 27). Switch status should read ON when steering wheel is
turned. If switch status is as specified, go to step 24). If switch
status is not as specified, go to DTC P0551 test.
9) Remove fuel cap. Install a fuel tank filler tube adapter
in place of fuel cap. Plug fuel filler tube adapter hose. Disconnect
and plug air filter-to-EVAP vent solenoid hose at air filter.
Disconnect intake manifold plenum-to-EVAP purge solenoid at intake
manifold plenum. Install a "T" fitting between vacuum hose and intake
manifold plenum. Connect hand-held pressure/vacuum pump to "T"
fitting. Go to next step.
CAUTION: DO NOT apply more than 0.57 psi in following step. Applying
more than specified psi can crack fuel tank.
NOTE: Ensure fuel tank is at least 1/4 full. The lower the fuel
level in fuel tank, the longer it takes to pressurize fuel
system.
10) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, apply\
0.42 psi. If scan tool reading reaches 0.42 psi, replace fuel cap. Go
to step 24). If reading does not reach 0.42 psi, go to next step.
11) Disconnect hand-held pressure/vacuum pump from "T"
fitting. Install an evaporative emission system tester in place of
vacuum held pump and apply 0.49 psi. Wait two minutes. If pressure
drops less than 0.20 psi, go to next step. If pressure drops 0.29 psi
or more, go to step 14).
12) Disconnect EVAP purge solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose and
apply 0.9 psi. If pressure is not maintained, check EVAP purge
solenoid for leak. If EVAP purge solenoid is okay, replace hose. Go to
step 24). If pressure is maintained, go to next step.
13) Disconnect EVAP vent solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose and
apply 0.9 psi. If pressure is not maintained, check EVAP vent solenoid
for leak. If EVAP vent solenoid is okay, replace hose. Go to step 24).
If pressure is maintained, replace EVAP canister. Go to step 24).
14) Ensure hoses are properly routed and connected. See M -
VACUUM DIAGRAMS article. Install hoses as necessary and go to step
24). If hoses are okay, go to next step.
15) Disconnect OFLV-to-EVAP canister hose at OFLV and EVAP
canister. Plug hose at OFLV end. Connect hand-held pressure/vacuum
pump to hose at EVAP canister end. Apply 0.9 psi. If pressure is not
maintained, replace hose. Go to step 24). If pressure is maintained,
go to next step.
16) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Connect hand-held pressure/vacuum pump to
OFLV. While monitoring scan tool, apply 0.42 psi. If scan tool reading
reaches 0.42 psi, go to next step. If reading does not reach 0.42 psi,
go to step 20).
17) Disconnect OFLV-to-EVAP canister hose at EVAP canister.
Connect hand-held pressure/vacuum pump to hose and apply 0.9 psi. If
pressure is not maintained, go to next step. If pressure is
maintained, go to step 19).
18) Disconnect EVAP purge solenoid-to-EVAP canister hose at

system.
3) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, apply\
0.42 psi. If scan tool reading reaches 0.42 psi, go to next step. If
reading does not reach 0.42 psi, go to step 8).
4) Disconnect EVAP canister purge hose. Connect Purge Flow
Indicator (MB995061) between EVAP canister and disconnected hose. Turn\
engine on and allow it to reach operating temperature. Turn all lights
and accessories off. Place transmission in Park or Neutral. Observe
purge flow indicator while increasing engine RPM several times. If
purge flow indicator reads less than 2.5 SCFH (20 cm(3)/sec), check
EVAP canister purge hose and EVAP canister port for clogging. If hose
and port are okay, check EVAP purge solenoid. See DTC P0443. If
solenoid is okay, replace EVAP canister. Go to step 20).
5) Using scan tool, read Engine Coolant Temperature (ECT)
sensor temperature (item 21). Compare scan tool reading with
temperature gauge reading. If readings are about the same, go to next
step. If readings are not about the same, go to DTC P0115 test.
6) Using a thermometer, check engine compartment ambient
temperature. Using scan tool, read Intake Air Temperature (IAT) sensor\
temperature (item 13). Compare IAT sensor and thermometer readings. If\
readings are not about the same, go to DTC P0110 test. If readings are
about the same, go to next step.
7) Using scan tool, read Power Steering Pressure (PSP) switc\
h
status (item 27). Switch status should read ON when steering wheel is
turned. If switch status is as specified, go to step 20). If switch
status is not as specified, go to DTC P0551 test.
8) Remove fuel cap. Install a fuel tank filler tube adapter
in place of fuel cap. Plug fuel filler tube adapter hose. Disconnect
and plug air filter-to-EVAP vent solenoid hose at air filter.
Disconnect intake manifold plenum-to-EVAP purge solenoid at intake
manifold plenum. Install a "T" fitting between vacuum hose and intake
manifold plenum. Connect hand-held pressure/vacuum pump to "T"
fitting. Go to next step.
CAUTION: DO NOT apply more than 0.57 psi in following step. Applying
more than specified psi can crack fuel tank.
NOTE: Ensure fuel tank is at least 1/4 full. The lower the fuel
level in fuel tank, the longer it takes to pressurize fuel
system.
9) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, apply\
0.42 psi. If scan tool reading reaches 0.42 psi, replace fuel cap. Go
to step 20). If reading does not reach 0.42 psi, go to next step.
10) Disconnect hand-held pressure/vacuum pump from "T"
fitting. Install an evaporative emission system tester in place of
vacuum held pump and apply 0.49 psi. Wait two minutes. If pressure
drops less than 0.20 psi, go to next step. If pressure drops 0.29 psi
or more, go to step 13).
11) Disconnect EVAP purge solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose and
apply 0.9 psi. If pressure is not maintained, check EVAP purge
solenoid for leak. If EVAP purge solenoid is okay, replace hose. Go to
step 24). If pressure is maintained, go to next step.
12) Disconnect EVAP vent solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose and
apply 0.9 psi. If pressure is not maintained, check EVAP vent solenoid
for leak. If EVAP vent solenoid is okay, replace hose. Go to step 20).
If pressure is maintained, replace EVAP canister. Go to step 24).
13) Ensure hoses are properly routed and connected. See M -

specified VSS connector terminal. See
VSS VOLTAGE FEED CIRCUIT IDENTIFICATION table. If voltage is not 4.5-
4.9 volts, replace PCM. If voltage is as specified, condition required
to set DTC is not present at this time. Go to next step.
VSS VOLTAGE FEED CIRCUIT IDENTIFICATION TABLE









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Application Terminal No.
Montero ................................................ 1
3000GT ................................................. 3









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9) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P0505: IDLE CONTROL SYSTEM FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Procedures are provided by manufacturer for component
testing using an engine analyzer with oscilloscope capability. Refer
to manufacturer's operation manual for instructions in use of
oscilloscope. If using engine analyzer, go to step 3). If using scan
tool, go to next step.
2) Using scan tool, read Idle Air Control (IAC) position
sensor step (item 45). See IAC POSITION SENSOR STEP SPECIFICATIONS
table. If scan tool does not read as specified, replace IAC position
sensor. If readings are as specified, go to step 5).
IAC POSITION SENSOR STEP SPECIFICATIONS TABLE









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A/C Switch Position Standard Step Value
Off ................................................. 2-25
Off To On ............................ Increase From 10-70
( 1) ................................... Increase From 5-50
( 1) - Brakes applied. A/C Off on Montero. A/C On on 3000GT.
Move gear selector lever to Drive position.









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NOTE: Check wave pattern when idle speed increases when A/C is
turned on. Wave pattern display lasts less than one second.
3) Disconnect IAC motor connector. Install Test Harness
(MB998463) between IAC motor and connector. Using engine analyzer with\
oscilloscope capability, connect special patterns probe in sequence to
test harness terminals No. 1 (Red clip), 3 (Blue clip), 4 (Black cl\
ip)
and 6 (Yellow clip) or PCM terminals No. 4, 5, 17 and 18 respectively.\
Start engine and allow it to idle. Turn A/C on. Compare oscilloscope
wave pattern with known-good wave pattern. See Fig. 44. Turn engine
off. If wave pattern is not normal, go to next step. If wave pattern
is normal, fault is intermittent. See INTERMITTENT DTCS.

2) Disconnect pressure hose from oil pump. See Fig. 45.
Install Adapter (MB990993) on oil pump. Install Adapter (MB990994) o\
n
disconnected hose. Connect Pressure Gauge (MB990662) and shutoff valve\
between adapters. Open shutoff valve. Bleed steering hydraulic system.
See HYDRAULIC SYSTEM BLEEDING in STEERING SYSTEM article.
Fig. 45: Testing PSP Sensor Circuit
Courtesy of Mitsubishi Motor Sales of America
3) Install a thermometer in fluid reservoir. Start engine and
allow it to idle. Turn steering wheel several times until fluid
temperature reaches 122-140
F (50-60C). Disconnect PSP switch
connector. Install a DVOM between ground and PSP switch terminal. See
Fig. 45 . Note continuity reading on DVOM. Go to next step.
4) With engine idling, gradually close shutoff valve to
increase power steering system pressure. Check pressure when PSP
switch is actuated by watching for a change in continuity. PSP switch