SsangYong Musso. Manual - part 116

1F-48 ENGINE CONTROLS

SSANGYONG  Y158

Circuit Description

When the ignition switch is turned ON, the Engine Con-
trol Module (ECM) will activate the pump relay and run
the in-tank fuel pump. The fuel pump will operate as
long as  the engine is cranking or running and the ECM
is receiving ignition reference pulses.

If there are no reference pulses, the ECM will shut off
the fuel pump within 1 second after the ignition switch
is turned ON, engine stopped or engine stalled.

Diagnostic Aids

An intermittent problem may be caused by a poor con-
nection, rubbed through wire insulation, or broken wire

inside the insulation.

FUEL PUMP RELAY CIRCUIT CHECK

Test Description

The number(s) below refer to specific step(s) on the
diagnostic table.

3. This step checks for the Engine Control Module

(ECM) providing ground for the operation of the fuel
pump relay.

7. By Confirming that the wiring is OK using steps 2

through 6, it can be determined that the fuel pump
relay is at fault.

9. After determining that there is no ground being pro-

vided by the ECM to the fuel pump relay, the fault is
either the ECM or the wiring between the ECM and
the fuel pump relay.

YAA1F39A

ENGINE CONTROLS 1F-49

SSANGYONG  Y158

1

1. Turn the ignition OFF for 10 seconds.
2. Turn the ignition ON.
3. Listen for in-tank fuel pump operation.
Does the fuel pump operate for the time specified?
1. Turn the ignition OFF.
2. Disconnect the fuel pump relay.
3. Connect a test light between the fuel pump relay

connector terminal 86 and ground.

4. Turn the ignition ON.
Is the test light ON?
1. Turn the ignition OFF.
2. Connect a test light between the fuel pump relay

connector terminal 85 and battery positive.

3. Turn the ignition ON.
4. With the ignition ON, the test light should light for

the time specified.

Is the test light ON?
Turn the ignition OFF.
Connect a test light between the fuel pump relay
connector terminal 30 and ground.
Is the test light ON?
Check for an open or short to ground in the wire
between the fuel pump relay connector terminal 87 and
the fuel pump terminal 2.
Is the problem found?
1. Repair the wire between the fuel pump relay

connector terminal 87 and the fuel pump terminal 2.

2. Install the fuel pump relay.
3. Turn the ignition ON.
Does the fuel pump operates for the time specified?
1. Replace the fuel pump relay.
2. Turn the ignition ON.
Does the fuel pump operate for the time specified?
Check for an open wire between the fuel pump relay
connector terminal 86 and the Over Voltage Protection
Relay (OVPR) connector terminal 7.
Is the problem found?
Check for an open wire between the fuel pump relay
connector terminal 85 and the Engine Control Module
(ECM) connector terminal 33.
Is the problem found?
1. Repair the wire between the fuel pump relay connector

terminal 85 and the ECM connector terminal 33.

2. Install the fuel pump relay.
3. Turn the ignition OFF for 10 seconds.
4. Turn the ignition ON.
Does the fuel pump operate for the time specified?

Step

Action

Value(s)

Yes

No

Fuel Pump Relay Circuit Check

2

3

1 sec

System OK

 Go to Step 2

1 sec

 Go to Step 4

 Go to Step 9

5

6

-

 Go to Step 3

 Go to Step 8

4

7

-

 Go to Step 10

 Go to Step 12

8

-

 Go to Step 5

 Go to Step 11

-

 Go to Step 6

 Go to Step 7

1 sec

System OK

-

1 sec

System OK

-

-

 Go to Step 13

Go to “OVPR

Circuit Check”

9

1 sec

System OK

-

10

1F-50 ENGINE CONTROLS

SSANGYONG  Y158

11

1. Repair the wire between the fuel pump relay

connector terminal 30 and battery.

2. Install the fuel pump relay.
3. Turn the ignition ON.
Does the fuel pump operate for the time specified?
1. Turn the ignition OFF.
2. Replace the ECM.
3. Turn the ignition ON.
Does the fuel pump operate for the time specified?
Repair the wire between the fuel pump relay connector
terminal 86 and the OVPR connector terminal 7.
Is the repair complete?

Step

Action

Value(s)

Yes

No

Fuel Pump Relay Circuit Check (Cont’d)

12

13

1 sec

System OK

-

1 sec

System OK

-

-

System OK

-

ENGINE CONTROLS 1F-51

SSANGYONG  Y158

BLANK