Sunday, June 7, 2020

2010 Cadillac Truck Escalade RWD V8-6.2L Page 1468

2010 Cadillac Truck Escalade RWD V8-6.2L Page 1468

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 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. The MCM does not need the CKP sensor signal in order

for the engine to start and run.

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 3 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.

Diagnostic Aids

With an ECM DTC P0335 set, the engine will only crank for about 2 seconds.

Reference Information

Schematic Reference

* Hybrid Controls Schematics ()