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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1997 🢒 Yukon - 4WD 🢒 Engine 🢒 Engine Controls - 6.5L 🢒 DTC P0103 Mass Air Flow (MAF) Sensor Circuit High Frequency

Object Number: 56429 Size: LF
Engine Controls Components
DIESEL PCM, MAF, EGR, APP, WASTEGATE
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The Mass Air Flow (MAF) sensor measures the amount of air entering the engine during a given time. The PCM uses the mass air flow information to monitor EGR flow rates. A large quantity of air entering the engine indicates an acceleration or high load situation, while a small quantity of air indicates deceleration or idle.

The MAF sensor produces a frequency signal. DTC P0101 will be set if the signal from the MAF sensor does not match a predicted value based on, engine coolant temperature, throttle angle and engine speed.

DTC P0103 will be set if the signal from the MAF sensor is above the possible range of a normally operating MAF sensor. This is a type B DTC.

Conditions for Setting the DTC
    • The engine is running.
    • Engine run time is greater than 2 seconds.
    • Engine Speed
    • Above conditions present for over 2 seconds.
    • MAF signal frequency is greater than 10496 Hertz

Action Taken When the DTC Sets
    • The PCM will illuminate the Malfunction Indicator Lamp (MIL) on the second consecutive fault.
    • The PCM will store conditions which were present when the DTC set as Freeze Frame and the Fail Records data.

Conditions for Clearing the MIL/DTC
    • The PCM will turn the MIL OFF on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present.
    • A history DTC P0103 will clear after 40 consecutive warm-up cycles have occurred without a fault.
    • DTC P0103 can be cleared by using the scan tool Clear Info function.

Diagnostic Aids

Check for the following conditions:

    • 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.
    • Damaged harness Inspect the wiring harness for damage. If the harness appears to be OK, observe the scan tool while moving connectors and wiring harnesses related to the MAF sensor A change in the display will indicate the location of the fault.

The Adaptive Learn Matrix (ALM) is used to adjust the EGR vacuum control based on Mass Air Flow (MAF). The ALM may change as a result of back pressure increases over the life of the vehicle or other engine system variations. The ALM is made up of sixteen cells (numbered from zero to fifteen) in which each cell covers a range of engine speed (RPM) and load (mm3).

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. This step verifies that the problem is present at idle.

    2.

  2. A frequency reading with the MAF sensor connector disconnected indicates an Electro-Magnetic Interference (EMI) related fault or a poor connection.

    3.

  3. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Step

Action

Value(s)

Yes

No

1

Important: Before clearing DTC(s) use the scan tool to record Freeze Frame and Failure Records for reference, as data will be lost when the Clear Info function is used.

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

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2
  1. Start the engine.
  2. With the engine idling, monitor the MAF display on the scan tool.

Is the MAF display above the specified value?

10496 Hz

Go to Step 4

Go to Step 3

3
  1. Turn the ignition ON, engine OFF.
  2. Review and record the scan tool Fail Records data.
  3. Operate the vehicle within the Fail Records conditions as noted.
  4. Using a scan tool, monitor the Specific DTC info for DTC P0103.

Does the scan tool indicate DTC P0103 Failed This Ign?

--

Go to Step 4

Refer to Diagnostic Aids

4
  1. Turn the ignition OFF.
  2. Disconnect the MAF sensor connector.
  3. Turn the ignition ON, engine idling.
  4. Using a scan tool, monitor the MAF display.

Does the scan tool indicate a MAF display at the specified value?

00 Hz

Go to Step 5

Go to Step 7

5
  1. Check for a poor connection at the MAF sensor harness terminals.
  2. If a poor connection is found, replace the terminal(s).

Was a poor connection found?

--

Go to Step 10

Go to Step 6

6

Replace the MAF sensor.

Is the action complete?

--

Go to Step 10

--

7
  1. Check the MAF sensor harness for incorrect routing. Verify the harness is not near aftermarket add-ons.
  2. If incorrect routing is found, correct harness routing.

Was a problem found?

--

Go to Step 10

Go to Step 8

8
  1. Check the MAF sensor signal circuit terminal connections at the PCM.
  2. If a poor connection is found, repair as necessary.

Was a poor connection found?

--

Go to Step 10

Go to Step 9

9

Replace the PCM.

Important: The new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 10

--

10
  1. Using the scan tool, select DTC, Clear Info.
  2. Start the engine and idle until normal operating temperature is reached.
  3. Select DTC, Specific, then enter the DTC number which was set.
  4. Operate the vehicle until the Scan Tool indicates that the diagnostic Ran.

Does the Scan Tool indicate that the diagnostic Passed?

--

Go to Step 11

Go to Step 2

11

Using the scan tool, select Capture Info, Review Info.

Are any additional DTCs displayed that have not been diagnosed?

--

Go to the Applicable DTC Table

System OK