Mitsubishi Montero (1998+). Manual - part 193

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

Application                                     Terminal No.

Montero  ................................................  1

3000GT  .................................................  3

         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

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.

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 clip)

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.

Fig. 44:  Identifying Know-Good IAC Motor Wave Pattern

Courtesy of Mitsubishi Motor Sales of America

         4) Disconnect IAC motor connector. Leave test harness

connected to IAC motor. Using DVOM, check resistance between test

harness terminals No. 2 (White clip) and either 1 (Red clip) or 3

(Blue clip), and between test harness terminals No. 5 (Green clip) and

either 4 (Black clip) or 6 (Yellow clip). Resistance should be 28-33

ohms at 68



F (20



C). If resistance is as specified, go to next step.

If resistance is not as specified, replace IAC motor. Go to step 10).

         5) On 3000GT, go to step 7). On Montero, disconnect IAC motor

connector and MFI relay connector. Check for continuity between IAC

motor connector terminal No. 2 and MFI relay connector terminal No. 1.

If continuity does not exist, repair wiring harness as necessary. If

continuity exists, go to next step.

         6) Check for continuity between IAC motor connector terminal

No. 5 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) Disconnect IAC motor connector. Turn ignition switch to ON

position. Check voltage between chassis ground and IAC motor connector

terminals No. 2 and 5. If battery voltage does not exist on either

circuit, repair wiring harness as necessary. If battery voltage exists

on both circuits, go to next step.

         8) Turn ignition switch to OFF position. Disconnect PCM

connector and IAC motor connector. Ground specified PCM connector

terminal and using DVOM, check continuity between chassis ground and

specified IAC motor connector terminal. See

PCM-TO-IAC MOTOR HARNESS CIRCUIT IDENTIFICATION  table. If continuity

does not exist, repair wiring harness as necessary. If continuity

exists, go to next step.

PCM-TO-IAC MOTOR HARNESS CIRCUIT IDENTIFICATION TABLE

PCM Terminal No.                      IAC Motor Terminal No.

14  .....................................................  1

15  .....................................................  4

28  .....................................................  3

29  .....................................................  6

         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.

         10) Road test vehicle and attempt to duplicate conditions

that caused original complaint. Recheck for DTCs. If no DTCs are

displayed, test is complete.

         DTC P0510:  CLOSED THROTTLE POSITION (TP) SWITCH FAILURE

NOTE:    Closed TP switch is built into TP sensor. For DTC P0510

         test purposes, TP sensor will be referred to as closed

         TP switch. For terminal identification, see TP sensor under

         TERMINAL IDENTIFICATION. For circuit and wire color

         identification, see L - WIRING DIAGRAMS article.

         1) If using scan tool, go to step 3). Disconnect closed TP

switch connector. Check for continuity between closed TP switch

connector terminals No. 1 and 2 on Montero or No. 3 and 4 on 3000GT.

Go to next step.

         2) Depress accelerator pedal. Continuity should not exist.

Release accelerator pedal. Continuity should exist. If continuity is

not as specified, replace TP sensor. If continuity is as specified, go

to step 4).

         3) Using scan tool, read closed TP switch state (item 26).

With accelerator pedal released, scan tool should read ON. With

accelerator pedal slightly depressed, scan tool should read OFF. If

closed TP switch does not test as specified, replace TP sensor. If

closed TP switch tests as specified, disconnect closed TP switch

connector and go to next step.

         4) On 3000GT, go to next step. On Montero, turn ignition

switch to OFF position. Disconnect PCM connector. Ground PCM connector

terminal No. 79. Using DVOM, check continuity between chassis ground

and closed TP switch connector terminal No. 2. If continuity does not

exist, repair wiring harness as necessary. If continuity exists, go to

next step.

         5) Check continuity between chassis ground and closed TP

switch connector terminal No. 1 on Montero or No. 4 on 3000GT. If

continuity does not exist, repair wiring harness as necessary. If

continuity exists, go to next step.

         6) Turn ignition switch to ON position. Check voltage between

chassis ground and closed TP switch connector terminal No. 2 on

Montero or No. 3 on 3000GT. If voltage is less than 4 volts, replace

PCM. If voltage is more than 4 volts, condition required to set DTC is

not present at this time. Go to next step.

         7) 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 P0551:  POWER STEERING PRESSURE (PSP) SENSOR CIRCUIT

         PERFORMANCE

NOTE:    For terminal identification, see TERMINAL IDENTIFICATION. For

         circuit and wire color identification, see

         L - WIRING DIAGRAMS article.

         1) Using scan tool, read Power Steering Pressure (PSP) status

(item 27). Switch status should read ON when steering wheel is turned.

If switch status is as specified, fault is intermittent. See

INTERMITTENT DTCS. If switch status is not as specified, go to next

step.

         2) Disconnect pressure hose from oil pump. See  Fig. 45.

Install Adapter (MB990993) on oil pump. Install Adapter (MB990994) on

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 (50-60



C). 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