P1AC7 GMC - Drive Motor 1 Control Module Crankshaft Position Sensor Performance

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3    What is this?
Table of contents

P1AC7 GMC Possible Causes

  • Faulty Drive Motor Generator Power Inverter Control Module (PIM)
  • Drive Motor Generator Power Inverter Control Module (PIM) harness is open or shorted
  • Drive Motor Generator Power Inverter Control Module (PIM) circuit poor electrical connection
  • Faulty Engine Control Module (ECM)

How do I fix code P1AC7 GMC?

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's pins.
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Tech Notes

If codes P0335 or P0336 are set, diagnose them prior to diagnosing this code.

Cost of diagnosing the P1AC7 GMC code

Labor: 1.0

The cost of diagnosing the P1AC7 GMC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle's make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.

Possible Symptoms

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

P1AC7 GMC Description

The crankshaft position (CKP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit and an output signal circuit. The CKP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 58-tooth reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced at 60-tooth spacing, with 2 missing teeth for the reference gap. The CKP sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the CKP sensor output depends on the velocity of the crankshaft. The CKP sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the ECM as each tooth on the wheel rotates past the CKP sensor. The ECM uses each CKP signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to sequence the ignition timing and fuel injection events for the engine. The ECM also uses CKP sensor output information to determine the crankshaft relative position to the camshaft, to detect cylinder misfire, and to control the CMP actuator if equipped.
Motor Control Module (MCM) 1 is also connected to the CKP sensor signal and low reference circuits. The MCM uses the CKP sensor output information to determine engine crankshaft position to aid in smooth engine Auto-starts.
OBDII Code P1ac7 Gmc - Drive Motor 1 Control Module Crankshaft Position Sensor Performance - AutoCodes.com

More Information

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