MBE 900 4000 Troubleshooting

Section 19.1 Description of SID 21 – Crankshaft Position Sensor Outside of Normal Operating Conditions

Section 19.1
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.

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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" .‪

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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 (-)‪

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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 (+)‪

Table 2. Selected Harness Pin Locations

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.‪

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 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


MBE 900/4000 Troubleshooting Guide - 6SE422
Generated on 10-13-2008

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