Hummer H2. Manual — part 1625

Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

z

The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles
that the diagnostic runs and does not fail.

z

A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

z

A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other
emission related diagnostic.

z

Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

z

When the vehicle is at ambient temperature the IAT sensor and the ECT sensor temperatures should be
relatively close to each other. Refer to Temperature vs Resistance .

z

If a short to a separate 5-volt source occurs this DTC may set.

z

If an intermittent condition is suspected, refer to Intermittent Conditions .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

6: This step tests for the proper operation of the circuit in the low voltage range.

DTC P0113

Step

Action

Values

Yes

No

Schematic Reference:Engine Controls Schematics
Connector End View Reference:Powertrain Control Module (PCM) Connector End Views or
Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check-
Engine Controls?

-

Go to Step 2

Go to Diagnostic

System Check -

Engine Controls

2

Observe the IAT sensor parameter with a scan tool.
Is the IAT sensor parameter less than the specified
value?

-38°C (-

36°F)

Go to Step 4

Go to Step 3

3

1. Observe the Freeze Frame/Failure Records data

for this DTC.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for

running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame/Failure Records.

-

Go to Diagnostic

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0068 To DTC P0141/P0161) - 4.8L, 5.3L, and 6.0L -

Hummer H2

Did the DTC fail this ignition?

Go to Step 4

Aids

4

1. Disconnect the mass air flow (MAF)/intake air

temperature (IAT) sensor.

2. Connect a DMM between the signal circuit of

the IAT sensor and a good ground.

Is the voltage more than the specified value?

5.2 V

Go to Step 5

Go to Step 6

5

Test the signal circuit for a short to voltage. Refer to
Circuit Testing and Wiring Repairs in Wiring
Systems.Did you find and correct the condition?

IMPORTANT:

The sensor may be damaged if the circuit is
shorted to a voltage source.

-

Go to Step 15

Go to Step 12

6

1. Connect a 3-amp fused jumper wire between

the signal circuit of the IAT sensor and the low
reference circuit of the IAT sensor. Refer to
Using Fused Jumper Wires in Wiring
Systems.

2. Observe the IAT sensor parameter with a scan

tool.

Is the IAT sensor parameter more than the specified
value?

128°C

(262°F)

Go to Step 10

Go to Step 7

7

1. Connect a 3-amp fused jumper wire between

the signal circuit of the IAT sensor and a good
ground. Refer to Using Fused Jumper Wires
in Wiring Systems.

2. Observe the IAT sensor parameter with a scan

tool.

Is the IAT sensor parameter more than the specified
value?

128°C

(262°F)

Go to Step 9

Go to Step 8

8

Test the signal circuit of the IAT sensor for an open
circuit or high resistance. Refer to Circuit Testing
and Wiring Repairs in Wiring Systems
Did you find and correct the condition?

-

Go to Step 15

Go to Step 12

9

Test the IAT sensor low reference circuit for high
resistance or an open. Refer to Circuit Testing and
Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

-

Go to Step 15

Go to Step 12

10

Test the IAT signal circuit for a short to any 5-volt
reference circuit. Refer to Circuit Testing and
Wiring Repairs in Wiring Systems.

-

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0068 To DTC P0141/P0161) - 4.8L, 5.3L, and 6.0L -

Hummer H2

DTC P0116

Circuit Description

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine
coolant. The powertrain control module (PCM) supplies 5 volts to the signal circuit and a ground for the ECT
low reference circuit. When the ECT is low, the sensor resistance is high. When the ECT is high, the sensor
resistance is low. The PCM uses this high side coolant rationality test to determine if the ECT input is skewed

Did you find and correct the condition?

Go to Step 15

Go to Step 11

11 Test for an intermittent and for a poor connection at

the IAT sensor. Refer to Testing for Intermittent
Conditions and Poor Connections and Connector
Repairs in Wiring SystemsDid you find and correct
the condition?

IMPORTANT:

The sensor may be damaged if the circuit is
shorted to a voltage source.

-

Go to Step 15

Go to Step 13

12

Test for an intermittent and for a poor connection at
the powertrain control module (PCM). Refer to
Testing for Intermittent Conditions and Poor
Connections and Connector Repairs in Wiring
Systems.
Did you find and correct the condition?

-

Go to Step 15

Go to Step 14

13

Replace the IAT sensor. Refer to Mass Air Flow
(MAF)/Intake Air Temperature (IAT) Sensor
Replacement .
Did you complete the replacement?

-

Go to Step 15

-

14

Replace the PCM. Refer to Powertrain Control
Module (PCM) Replacement .
Did you complete the replacement?

-

Go to Step 15

-

15

1. Clear the DTCs with a scan tool.

2. Turn OFF the ignition for 30 seconds.

3. Start the engine.

4. Operate the vehicle within the Conditions for

Running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

-

Go to Step 2

Go to Step 16

16

Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?

-

Go to

Diagnostic

Trouble Code

(DTC) List

System OK

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0068 To DTC P0141/P0161) - 4.8L, 5.3L, and 6.0L -

Hummer H2

high. The internal clock of the PCM will record the amount of time the ignition is OFF. At restart the PCM will
compare the temperature difference between the ECT and the intake air temperature (IAT). Before failing this
test the PCM will perform a calculation to determine the presence of a block heater. If the PCM detects that the
temperature difference is not within the calibrated range after the ignition OFF time, DTC P0116 sets.

Conditions for Running the DTC

z

The ignition is ON.

z

DTCs P0112, P0113, P0117, P0118, P0125, P0128, P0601, P0602, P1621, P1683 are not set.

z

The start-up IAT is more than 15°C (59°F).

z

The vehicle has a minimum ignition OFF time of 10 hours.

z

This DTC will only run once during the ignition cycle within the enabling conditions.

Conditions for Setting the DTC

If the PCM detects a temperature difference between the ECT sensor and the IAT sensor of more than 15°C
(27°F), then the vehicle must be driven for more than 400 seconds over 24 km/h (15 mph). If the IAT sensor
temperature decreases more than 3°C (5°F), a block heater is detected and the test is aborted. If the IAT sensor
temperature does not decrease, a block heater was not detected and DTC P0116 sets.

Action Taken When the DTC Sets

z

The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition
cycle that the diagnostic runs and fails.

z

The control module records the operating conditions at the time the diagnostic fails. The first time the
diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic
reports a failure on the second consecutive ignition cycle, the control module records the operating
conditions at the time of the failure. The control module writes the operating conditions to the Freeze
Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

z

The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles
that the diagnostic runs and does not fail.

z

A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

z

A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other
emission related diagnostic.

z

Clear the MIL and the DTC with a scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

7: A snapshot is the quickest method to capture the data before it changes.

8: An IAT sensor that is skewed low can cause this DTC to set.

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls Diagnosis (DTC P0068 To DTC P0141/P0161) - 4.8L, 5.3L, and 6.0L -

Hummer H2