Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 341

6E–394

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

the condition that caused the DTC to be set occurs.  This
may assist in diagnosing the condition.

Engine Coolant Temperature Sensor

°

C

°

F

OHMS

Temperature vs. Resistance Values

(approximate)

100

212

177

80

176

332

60

140

667

45

113

1188

35

95

1802

25

77

2796

15

59

4450

5

41

7280

–5

23

12300

–15

5

21450

–30

–22

52700

–40

–40

100700

DTC P1114 – ECT Circuit Intermittent Low Voltage

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

Is DTC P0117 also set?

—

Go to 

DTC

P0117 first

Go to 

Step 3

3

1. Check the ECT signal circuit between the ECT

sensor connector and the PCM for an intermittent
short to ground.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Refer to

Diagnostic

Aids

6E–395

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P1115 ECT Sensor Circuit Intermittent High Voltage

060R200053

Circuit Description

The engine coolant temperature (ECT) sensor is a
thermistor mounted in the engine coolant stream.  The
powertrain control module (PCM) applies a voltage
(about 5.0 volts) through a pull-up resistor to the ECT
signal circuit.  When the engine coolant is cold, the sensor
(thermistor) resistance is high, therefore the PCM will
measure a high signal voltage.  As the engine coolant
warms, the sensor resistance becomes less, and the
ECT signal voltage measured at the PCM drops.  With a
fully warmed up engine, the ECT signal voltage should
measure about 1.5 to 2.0 volts.  If the PCM detects an
ECT signal that is intermittently above the range of the
ECT sensor, DTC P1115 will set.

Conditions for Setting the DTC

D

Engine running time longer than 90 seconds.

D

The ECT sensor signal is intermittently greater than
–39

°

C (–38

°

F) (about 5 volts) for a total of 10 seconds

over a 100-second period.

Action Taken When the DTC Sets

D

The PCM will not illuminate the malfunction indicator
lamp (MIL).

D

The PCM will store conditions which were present
when the DTC was set as Failure Records data only.
This information will not be stored as Freeze Frame
data.

Conditions for Clearing the MIL/DTC

D

A history DTC P1115 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

D

DTC P1115 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at PCM – Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

D

Damaged harness – Inspect the wiring harness for
damage.  If the harness appears to be OK, observe the
ECT display on the Tech 2 while moving connectors
and wiring harnesses related to the ECT sensor.  A
change in the ECT display will indicate the location of
the fault.

Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often

6E–396

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

the condition that caused the DTC to be set occurs.  This
may assist in diagnosing the condition.

Engine Coolant Temperature Sensor

°

C

°

F

OHMS

Temperature vs. Resistance Values

(approximate)

100

212

177

80

176

332

60

140

667

45

113

1188

35

95

1802

25

77

2796

15

59

4450

5

41

7280

–5

23

12300

–15

5

21450

–30

–22

52700

–40

–40

100700

6E–397

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P1115 – ECT Sensor Circuit Intermittent High Voltage

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

Is DTC P0118 also set?

—

Go to 

DTC

P0118 chart

first

Go to 

Step 3

3

Is DTC P1111 also set?

—

Go to 

Step 8

Go to 

Step 4

4

1. Check for a poor sensor ground circuit terminal

connection at the ECT sensor.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 5

5

1. Check for a poor ECT signal circuit terminal

connection at the ECT sensor.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 6

6

1. Check the ECT signal circuit between the ECT

sensor connector and the PCM for an intermittent
open.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 7

7

1. Check the ECT signal circuit between the ECT

sensor connector and the PCM for an intermittent
short to voltage.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 8

8

1. Check for a poor sensor ground circuit terminal

connection at the PCM.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 9

9

1. Check for an intermittent open or a faulty splice in

the sensor ground circuit.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Refer to

Diagnostic

Aids