Description of SID 21 – Crankshaft Position Sensor Outside of Normal Operating Conditions
SID 021 indicates that the PLD-MR control unit has detected the Crankshaft Position (CKP) sensor operating outside of normal operating conditions.
The diagnostic condition is typically:
- CKP Sensor Signal Voltage Too Low (021 01)
- CKP Sensor Open Circuit (021 03)
- CKP Sensor Short to Ground (021 04)
- No Match of Camshaft and Crankshaft Signals (021 07)
- CKP Sensor Time Out (021 08)
- CKP Sensor Pins Swapped (021 14)
See Figure “Sensor Location on MBE 6-Cylinder Engine” for sensor locations on the typical MBE 6-cylinder engine.
Note: Sensor locations are similar on the 4-cylinder engine. The Engine Oil Level (EOL) sensor, if used, is located at the bottom of the oil pan.
Note: * The Baro sensor is integrated into the PLD-MR unit.
|1. Engine Oil Pressure (EOP) Sensor||5. Barometric Pressure (Baro) Sensor *|
|2. Engine Coolant Temperature (ECT) Sensor||6. Camshaft Position (CMP) Sensor – on Cylinder Block |
|3. Intake Manifold Pressure (IMP) Sensor||7. CKP Sensor – on Timing Case|
|4. Supply Fuel Temperature (SFT) Sensor|||
Figure 1. Sensor Location on MBE 6-Cylinder Engine
The engine harness is delivered to the factory with the engine sensors and the PLD-MR already connected. See Figure “Typical On-Highway Six-Cylinder Engine Harness” for a typical six-cylinder engine harness. Engine harness sensor pin locations are listed in Table “Selected Harness Pin Locations” .
Figure 2. Typical On-Highway Six-Cylinder Engine Harness
|Pin ||Wire Color ||Signal Type ||Function ||Connector |
|6- Cylinder ||4- Cylinder |
|1||Blk/Yel||Blk/Yel||Sensor Return||CMP Sensor (-)||
Front Looking into the Pins
|2||Blk/Viol||Blk/Viol||Sensor Return||CKP Sensor (-)|
|19||Brn/Viol||Brn/Viol||Frequency Input||CKP Sensor (+)|
|20||Brn/Yel||Brn/Yel||Frequency Input||CMP Sensor (+)|
The CKP sensor and its bracket are located on the flywheel housing. See Figure “Crankshaft Position Sensor and Bracket Location” . In most cases the CKP sensor bracket is replaced only when the flywheel housing is replaced.
|1. CKP Sensor Bracket||4. CKP Sensor|
|2. Shear Bolt (2 Qty.)||5. Reference Hole on Flywheel Edge|
|3. Spring Bushing|||
Figure 3. Crankshaft Position Sensor and Bracket Location