P1AC6
DTC P1AC6 or P1AC7
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptor
DTC P1AC6
- Drive Motor 1 Control Module Crankshaft Position (CKP) Sensor Circuit
DTC P1AC7
- Drive Motor 1 Control Module Crankshaft Position Sensor Performance
Diagnostic Fault Information
Circuit/System Description
The crankshaft position (CKP) sensor is located on the rear of bank 1 of the engine block. The CKP sensor is a hall effect switch that works in conjunction with a 58X reluctor wheel that is attached to the crankshaft. Each tooth on the reluctor wheel is spaced 6 degrees apart with one span having a 12 degree space. The engine control module (ECM) uses the 12 degree space to determine top dead center (TDC) for cylinders 1 and 4. The ECM determines when cylinder 1 is on the compression stroke by monitoring the CKP sensor and the camshaft position (CMP) sensors. The ECM can synchronize the ignition timing, fuel injector timing, and spark knock control based on the CKP sensor and the CMP sensor inputs.
Conditions for Running the DTC
P1AC6 and P1AC7
* Drive motor generator 1 is rotating.
* The DTC runs continuously when the above conditions are met.
Conditions for Setting the DTC
P1AC6
The MCM detects no engine speed signal for 2 seconds.
P1AC7
The MCM detects an invalid engine speed signal for 7 seconds.
Action Taken When the DTC Sets
DTCs P1AC6 and P1AC7 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P1AC6 and P1AC7 are Type B DTCs.
Reference Information
Schematic Reference
* Hybrid Controls Schematics (Electrical Diagrams)
* Engine Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
Inspect for ECM DTCs P0335, P0336 or P0338. With the engine running, observe the hybrid powertrain control module (HPCM) Engine Speed parameter with a scan tool. The parameter should display the current engine speed, matching the tachometer and/or the ECM Engine Speed parameter.
If ECM DTCs P0335, P0336 or P0338 are set, diagnose them prior to diagnosing the HPCM DTC.
If the HPCM Engine Speed parameter displays a value other than the current engine speed, continue with Circuit/System Testing.
Circuit/System Testing
Attempt to crank and start the engine. Perform the appropriate diagnostic procedure as necessary.
Diagnosis if the Engine Does NOT Start
1. Ignition OFF, disconnect the CKP sensor connector.
2. Ignition ON, test for 4.8-5.2V on the CKP signal circuit, from the CKP connector terminal A and ground.
• If within the specified range, reconnect the CKP connector and perform ECM DTC P0335 diagnostic procedure.
3. Ignition OFF, disconnect PIM connector X1.
4. Ignition ON, test for 4.8-5.2V on the CKP signal circuit, from the CKP sensor connector terminal A and ground.
• If within the specified range, replace the drive motor generator power inverter control module (PIM).
5. Test the CKP signal circuit between CKP connector terminal A and PIM connector X1 terminal 26 for a short to ground if less than the specified value or a short to voltage if greater than the specified value.
• If the circuit tests normal, reconnect all connectors and perform ECM DTC P0335 diagnostic procedure.
Diagnosis if the Engine Starts
Note: Diagnose ECM DTCs P0335 and P0336 prior to performing this procedure.
1. Ignition OFF, disconnect PIM connector X1 and the CKP sensor connector.
2. Test for less than 5 ohms on the CKP low reference circuit, from connector X1 terminal 35 and ground.
• If greater than the specified value, repair the low reference circuit for an open/high resistance.
3. Ignition ON, test for 4.8-5.2V on the CKP signal circuit, from the connector X1 terminal 26 and ground.
• If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the drive motor generator power inverter control module (PIM).
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning) for PIM replacement, programming, and setup