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CM850 Electronic Control System – 018-001   Specifications

General Information

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 WARNING 

This diagram is provided as a diagnostic tool for trained, experienced technicians only. Improper troubleshooting or repair can result in severe personal injury or death or property damage. See important instructions in Service Manual.

Electrical Specifications

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DATA LINK
Positive wire to chassis ground (J1587 only)
3.5 to 5.0 VDC
Negative wire to chassis ground (J1587 only)
0.0 to 2.5 VDC
J1939 BACKBONE RESISTANCE
Positive wire to return wire
50 to 70 Ohms
J1939 Termination Resistance
110 to 130 Ohms
ALL CONTINUITY CHECKS
OK (no open circuit) if less than 10 Ohms
ALL SHORTS TO GROUND
OK (no short circuit) if more than 100k Ohms
SHORT CIRCUIT TO EXTERNAL VOLTAGE
OK if less than 1.5 VDC
SENSOR SUPPLY VOLTAGE
@ ECM = 4.75 to 5.25 VDC
SOLENOIDS
EFC Actuator = 2.0 to 4.5 Ohms
ECM CONNECTOR
Retaining Cap Screw Torque = 2.8 N•m [25 in-lb]

Sensor Specifications

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NOTE: To convert to gauge pressure on all psi pressure sensors subtract the barometric pressure from the absolute pressure.

BAROMETRIC (AMBIENT)
AIR PRESSURE SENSOR
Altitude [m] Altitude [ft] Pressure [psi] Pressure [in Hg] Voltage (VDC)
0 (sea level) 0 14.7 29.9 3.65 to 4.28
915 3000 13.2 28.9 3.06 to 3.50
1830 6000 11.8 24.0 2.52 to 2.96
2744 9000 10.5 21.4 2.01 to 2.36
3659 12000 9.35 19.0 1.57 to 1.84
INTAKE MANIFOLD PRESSURE SENSOR
Torque = 23 N•m [204 in-lb]
Pressure (mm Hg) Pressure [in Hg] Pressure [psi] Voltage (VDC)
0 0 0 0.90 to 1.06
381 15 22 1.30 to 1.53
635 25 27 1.57 to 1.84
1549 61 45 2.53 to 2.96
2057 81 55 3.07 to 3.60
2590 102 65 3.61 to 4.23
TURBOCHARGER COMPRESSOR INLET AIR TEMPERATURE AND INTAKE MANIFOLD TEMPERATURE SENSORS
Torque = 23 N•m [204 in-lb]
Temperature (C°) Temperature [F°] Resistance (Ohms)
-10 14 49k to 62k
0 32 29k to 36k
20 68 11k to 14k
40 104 4.9k to 5.8k
70 158 1.6k to 1.9k
EXHAUST GAS PRESSURE SENSOR
Torque = 23 N•m [204 in-lb]
Pressure (mmHg) Pressure [inHg] Pressure [psi] Voltage (VDC)
0 0 0 0.5 to 0.54
381 15 7 0.57 to 0.68
635 25 12 0.7 to 0.98
1549 61 30 1.48 to 1.8
2057 81 40 1.85 to 2.42
3886 153 75 3.53 to 4.21
EGR TEMPERATURE SENSOR
Torque = 57 N•m [42 ft-lb]
Temperature (C°) Temperature [F°] Resistance (Ohms)
0 32 256k to 423k
20 68 99k to 154k
40 104 42k to 63k
100 212 5.5k to 7.1k
140 284 1.9k to 2.3k
200 392 520 to 580
FUEL RAIL PRESSURE SENSOR
Torque = 70 N•m [52 ft-lb]
Pressure (mPa) Pressure [psi] Voltage (VDC)
0 0 0.50
40 5801 1.39
70 10153 2.06
100 14504 2.72
140 20305 3.61
180 26107 4.50
ENGINE COOLANT TEMPERATURE SENSOR
Torque = 23 N•m [204 in-lb]
Temperature (C°) Temperature [F°] Resistance (Ohms)
0 32 30k to 37k
25 77 9.3k to 10.7k
50 122 3.2k to 3.8k
80 176 1.1k to 1.3k
95 203 700 to 800
TURBOCHARGER SPEED SENSOR
Torque = 8.5 N•m [75 in-lb]
ENGINE SPEED SENSOR
Torque = 25 N•m [221 in-lb]
CAMSHAFT POSITION SENSOR
Torque = 9.5 N•m [84 in-lb]
EGR POSITION SENSOR AND TURBOCHARGER POSITION SENSOR CAP SCREWS
Torque = 1.7 N•m [15 in-lb]
VEHICLE SPEED SENSOR
Torque = 34 N•m [25 ft-lb]
OIL PRESSURE SWITCH
Torque = 23 N•m [204 in-lb]
ACCELERATOR PEDAL (IVS, ISS, AND APS)
Idle validation circuit resistance:
For ON and OFF Idle states
IVS – Maximum closed circuit resistance less than 10 Ohms
ISS – Maximum closed circuit resistance less than 125 Ohms
IVS and ISS – Minimum open circuit resistance less than 100k Ohms
Accelerator Position Coil Resistance:
Between supply and return pins = 2000 to 3000 Ohms
Between supply and signal pins (pedal released) = 1500 to 3000 Ohms
Between supply and signal pins (pedal depressed) = 200 to 1500 Ohms

NOTE: Released resistance minus depressed resistance must be 1000 Ohms.
Last Modified:  04-May-2004
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