Isuzu Rodeo UE. Service manual - part 593

8D–220

WIRING SYSTEM

Circuit Diagram – 6

D08RX127

8D–221

WIRING SYSTEM

Parts Location

D08RX133

Legend

(1) H–2
(2) H–12, H–13, H–14, H–19
(3) I–41, I–42
(4) Alarm & Relay Control Unit
(5) E–6
(6) M–11
(7) M–10
(8) B–8
(9) I–1

(10) I–10

(11) Combination Meter

(12) I–2
(13) I–9
(14) I–7

(15) I–14
(16) Fuel Tank Unit
(17) Fuel Tank
(18) C–16
(19) H–15, H–16, H–17, H–31, H–32
(20) C–6
(21) H–5, H–6
(22) B–23
(23) M–3, M–4
(24) M–12
(25) H–10
(26) C–15
(27) E–1
(28) M–1, M–2

8D–222

WIRING SYSTEM

Diagnosis

Speedometer

Speedometer and Odometer Do Not Function

Step

Action

Value(s)

Yes

No

1

Does the vehicle speed sensor output in 4 pulses/1
rotation?

—

Go to Step 2

Replace the

vehicle speed

sensor

2

Are the circuits between the vehicle speed sensor and
the meter, and the fuse (11) and the ground normal?

—

Replace the

speedometer

Repair a poor

connection at

the

connectors or

an open

circuit in the

circuit

Speedometer Does Not Function (Odometer Is Normal)

Step

Action

Value(s)

Yes

No

1

Replace the speedometer assembly

Is the action complete?

—

Verify repair

—

Odometer Does Not Function (Speedometer Is Normal)

Step

Action

Value(s)

Yes

No

1

Replace the speedometer assembly

Is the action complete?

—

Verify repair

—

Speedometer Needle Fluctuates (May Be Wide Fluctuation)

Step

Action

Value(s)

Yes

No

1

Does the vehicle speed sensor normally?

—

Go to Step 2

Replace the

speedometer

2

1. The oscilloscope waveform is deformed.
2. Replace the vehicle speed sensor, or repair a poor

connection at the connectors in the circuit or a
failure in the cable harness.

Is the action complete?

—

Verify repair

—

Speedometer Needle Jumps Erratically

Step

Action

Value(s)

Yes

No

1

Does the vehicle speed sensor output normally?

—

Go to Step 2

Replace the

speedometer

2

An abnormal perodic waveform is output by
oscilloscope.
Replace the vehicle speed sensor, or repair a poor
connection at the connectors in the circuit or a failure in
the cable harness.

Is the action complete?

—

Verify repair

—

8D–223

WIRING SYSTEM

Inspection Of Waveform By Oscilloscope

Step

Action

Value(s)

Yes

No

1

1. Disconnect the battery ground cable.
2. Remove four screws of the meter assembly.
3. Connect a resistance of 1.3 to 5k ohm (1.4W or

more) between the harness side connector I–1
terminal 12 and I–2 terminal 12 of the meter.

4. Install a speedometer tester.
5. Turn on the starter SW.
6. Check the waveform at the time when the vehicle

speed is at 37 mph.

Is the pulse input normal?

—

Replace the

speedometer

Replace the

vehicle speed

sensor, or

repair a poor

connection of

the

connectors in

the circuit or

a failure in

the cable

harness.

Tachometer

Tachometer Needle Fluctuates (May Be Wide Fluctuation)

Step

Action

Value(s)

Yes

No

1

Is the pulse input normal?

—

Replace the

tachometer

Go to Step 2

2

Replace the PCM, repair a poor connection of the
connector in the circuit or a failure in the cable harness.

Is the action complete?

—

Verify repair

—

Tachometer Needle Jumps Erratically

Step

Action

Value(s)

Yes

No

1

Is the pulse input normal?

—

Replace the

tachometer

Go to Step 2

2

Replace the ignition control module, or repair a poor
connection of the connector in the circuit or a failure in
the cable harness.

Is the action complete?

—

Verify repair

—

Engine Coolant Temperature Gauge

Needle Does Not Move

Step

Action

Value(s)

Yes

No

1

Is the connector of the engine coolant temperature unit
connected securely?

—

Go to Step 2

Connect the

connector

securely

2

Disconnect the connector of the engine coolant
temperature unit.
Connect a 3.4 W bulb between the harness side
connector E–19 terminal 1 and the ground of the
thermo unit.

When the starter SW is turned ON, does the gauge
pointer move about 10 seconds after that?

—

Go to Step 3

Go to Step 4