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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2005 🢒 TopKick C-Series (Conventional) C6/C7/C8 🢒 Engine 🢒 Engine Controls - 7.8L 🢒 DTC P2005

Circuit Description

The power take off (PTO) accelerator sensor up filter installed detects the PTO control signal voltage. The engine control module (ECM) receives the PTO control signal voltage from the sensor and controls the fuel injection quantity, engine speed during PTO. The PTO accelerator has the following circuits:

    • A 5-volt reference circuit
    • A low reference circuit
    • A PTO accelerator sensor signal circuit

The ECM supplies 5 volts to the PTO accelerator sensor on the 5-volt reference circuit. The ECM also provides a ground on the low reference circuit. The ECM monitors the PTO accelerator sensor signal for voltage outside the normal range of the PTO accelerator sensor. If the ECM detects an excessively high PTO accelerator sensor signal voltage, this DTC will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2005 Power Take Off (PTO) Accelerator Sensor Circuit High Voltage

Conditions for Running the DTC
    • The ignition switch is ON.
    • The battery voltage is between 10-16 volts.

Conditions for Setting the DTC

The ECM detects that the PTO accelerator sensor signal voltage is more than 4.9 volts.

Action Taken When the DTC Sets
    • The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
    • The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records.
    • The ECM inhibits PTO control.

Condition for Clearing the DTC
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
    • If an intermittent condition is suspected, the following may cause an intermittent:
       - Poor connections
       - A misrouted harness
       - Rubbed through wire insulation
       - Broken wire inside the insulation
    • Inspect for the following conditions:
       - Poor connection at ECM--Inspect the harness connectors for the following conditions:
   • Backed-out terminals
   • Improper mating
   • Broken locks
   • Improperly formed or damaged terminals
   • Poor terminal to wire connection
       - Damaged harness--Inspect the wiring harness for damage. If the harness appears to be OK, observe the PTO Accelerator display on the scan tool while moving the connectors and the wiring harness related to the sensor. A change in the display will indicate the location of the fault.

Test Description

The number below refers to the step number on the diagnostic table.

  1. Operate the vehicle within the same conditions as when the DTC failed. If you cannot duplicate the DTC, using the information included in the Failure Records can help to locate an intermittent condition.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install 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 3

Go to Diagnostic Aids

3
  1. Turn OFF the ignition.
  2. Disconnect the power take off (PTO) accelerator sensor connector.
  3. Connect the DMM between the signal circuit and the low reference circuit.
  4. Turn ON the ignition, with the engine OFF.

Is the DMM voltage more than the specified value?

4.5-5.5 V

Go to Step 6

Go to Step 4

4
  1. Turn OFF the ignition.
  2. Disconnect the PTO accelerator sensor connector.
  3. Connect a DMM between the 5-volt reference circuit and a low reference circuit.
  4. Turn ON the ignition, with the engine OFF.

Is the DMM voltage more than the specified value?

4.5-5.5 V

Go to Step 7

Go to Step 5

5
  1. Turn OFF the ignition.
  2. Disconnect the PTO accelerator sensor connector.
  3. Connect a DMM between the 5-volt reference circuit and a known good ground.
  4. Turn ON the ignition, with the engine OFF.

Is the DMM voltage more than the specified value?

4.5-5.5 V

Go to Step 9

Go to Step 8

6

Important: The PTO accelerator sensor may be damaged if the circuit is shorted to a voltage source.

  1. Test the signal circuit between the engine control module (ECM) and the PTO accelerator sensor for a short to voltage circuit
  2. Repair the circuits, as necessary.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 10

7
  1. Test the 5-volt reference circuit between the ECM and the PTO accelerator sensor for a short to battery voltage circuit.
  2. Repair the circuits, as necessary.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 10

8
  1. Test the low reference circuit between the ECM and the PTO accelerator sensor for an open circuit or for high resistance.
  2. Repair the circuits, as necessary.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 10

9
  1. Turn OFF the ignition.
  2. Disconnect the PTO accelerator sensor connector.
  3. Inspect for poor connections at the harness connector of the PTO accelerator sensor.
  4. Repair the connections, as necessary.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 11

10
  1. Turn OFF the ignition.
  2. Disconnect the ECM.
  3. Inspect for poor connections at the harness connector of the ECM.
  4. Repair the connections, as necessary.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

11

Replace the PTO.

Did you complete the replacement?

--

Go to Step 13

--

12

Important: The new ECM must be programmed.

Replace the ECM. Refer to Engine Control Module Programming and Setup , Engine Control Module Replacement/Restore Fuel Rate Data , and Fuel Injector Flow Rate Programming .

Did you complete the replacement?

--

Go to Step 13

--

13
  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 14

14

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK