Engine-Codes - Chevrolet - P1651 Chevrolet

P1651 Chevrolet Code - PCM Output Controls Fault

- Code Popularity: 18,577 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P1651 Chevrolet?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Powertrain Control Module (PCM)
  • Powertrain Control Module harness is open or shorted
  • Powertrain Control Module circuit poor electrical connection
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How to Fix the DTC P1651 Chevrolet?

Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

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What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P1651 Chevrolet code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

What Does the P1651 Chevrolet Code Mean?

The Quad Driver Module (QDM) is an electronic switch that completes a ground circuit when switched on. The QDM independently controls 4 separate outputs. A load is connected between battery voltage and the QDM allowing QDM driver to control the output. Each QDM has a fault detection logic that compares its input and output voltages. The logic expects to measure less than 3 volts when the QDM is on and greater than 7 volts when off. The QDM has only one fault that will detect a fault on any of the 4 outputs. The scan tool can be used to cycle the outputs on and off. It can also perform automated test which can isolate the faulty circuit.
The Diagnostic Trouble Code (DTC) P1650 and P1651 will set if there is an open, short to ground or short to voltage on any of the QDM output circuits, faulty MIL circuit, faulty upshift light circuit, faulty cooling fan relay circuit or A/C relay circuit. Fault detected for 5 seconds will set P1651. Fault detected for 20 seconds will set P1650. The QDM circuit is continuously checked when the engine is running.
The Quad Driver Module (QDM) is part of the Powertrain Control Module (PCM).

P1651 Chevrolet Code - PCM Output Controls Fault

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