COMPONENT LOCATION
GENERAL DESCRIPTION

The ECM provides ground to one side of the coil of the main relay and the other side is connected to the battery. The ECM monitors battery voltage and the voltage after the main relay.

DTC DESCRIPTION

Checking the contolling state of main relay every 10 sec. under detecting condition, if open or short in the circuit is detected for more than 5 sec., PCM sets P0685.

DTC DETECTING CONDITION

Item

Detecting Condition

Possible cause

DTC Strategy

●

Detects a short to ground, to battery or open circuit on the main relay

●

Poor Connection

●

Open or short in control circuit

●

Faulty Main Relay

●

Faulty PCM

EnableConditions

●

Engine Running

●

11V ≤ Ignition Voltage ≤ 16V

Threshold value

●

Open or Short in circuit

DiagnosisTime

●

Contineous

(More than 5sec. failure for every 10 sec. test)

MIL On Condition

●

DTC only (NO MIL ON)

※If Main relay has a fault(ex. Open) under engine running, the DTCs,P0638/P0685/P1295/P2106, can happen at the same time.

＜DTC Name＞

-

P0638 Throttle Actuator Control Range/Performance(Bank 1)

-

P0685 PCM/PCM Power Relay Control Circuit /Open

-

P1295 Throttle Actuator Control System - Power Management

-

P2106 Throttle Actuator Control System - Forced Limited Power

SPECIFICATION

Coil Resistance

70Ω ~ 120Ω

SCHEMATIC DIAGRAM
MONITOR DTC STATUS
1.

Check DTC Status

(1)

Connect scantool to Data Link Connector(DLC).

(2)

IG "ON".

(3)

Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC's information from the DTCs menu

(4)

Read "DTC Status" parameter.

(5)

Is parameter displayed "Present fault"?

▶ Go to "Terminal and connector inspection" procedure.

▶ Fault is intermittent caused by poor contact in the sensor’s and/or PCM’s connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

TERMINAL AND CONNECTOR INSPECTION
1.

Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

2.

Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

3.

Has a problem been found?

▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure

▶ Go to " Power Circuit Inspection " procedure.

POWER CIRCUIT INSEPCTION
1.

IG "OFF"

2.

Disconnect Main Relay

3.

IG "ON" & ENG "OFF".

4.

Measure the voltage between terminal 30 of main relay harness connector and chassis ground.

5.

Measure the voltage between terminal 86 of main relay harness connector and chassis ground.

Specification : B+

6.

Is the measured voltage within specification ?

▶ Go to "Control Circuit Inspecition" procedure.

▶ Check fuse between battery and main relay is disconnected.

▶ Repair or replace open or short in harness and then go to "Verification of Vehicle Repair" procedure.

CONTROL CIRCUIT INSPECTION
1.

Check short in harness

(1)

IG "OFF".

(2)

Disconnect Main Relay and PCM connector.

(3)

Measure resistance between terminal 85 of Main Relay and chassis ground.

(4)

Measure resistance between terminals 86 and 85 of Main Relay.

Specification : Infinite

(5)

Is the measured resistance within specification ?

▶ Go to "Check open in coil control" as follows.

▶ Repair or replace as necessary and then go to " Verification of Vehicle Repair" procedure.

2.

Check open in harness

(1)

IG "OFF".

(2)

Disconnect Main Relay and PCM connector.

(3)

Measure resistance between harness terminal 85 of Main Relay and harness terminal 43 of PCM harness connector.

Specification : Approx. below 1Ω

(4)

Is the measured resistance within specifications ?

▶ Go to "Component Inspection" procedure.

▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.

COMPONENT INSPECTION
1.

Check Main relay

(1)

IG "OFF".

(2)

Disconnect the main relay.

(3)

Measure the resistance between terminal 30 and 87 of main relay.

(4)

Measure the resistance between terminal 85 and 86 of main relay.

Specification :

Terminal

continuity

30~87

NO

85~86

YES (Approx. 70Ω ~ 120Ω)

(5)

Is the measured reisistance within specification ?

▶ Substitute with a known - good PCM and check for proper operation.

If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.

note

There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM.

▶ Substitute with a known - good Main Relay and check for proper operation.

If the problem is corrected, replace Main Relay and go to "Verification of Vehicle Repair"procedure.

VERIFICATION OF VEHICLE REPAIR

After a repair, it is essential to verify that the fault has been corrected.

1.

Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode

2.

Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions

3.

Read "DTC Status" parameter

4.

Is parameter displayed "History(Not Present) fault"?

▶ System performing to specification at this time. Clear the DTC.

▶ Go to the applicable troubleshooting procedure.

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