TROUBLESHOOTING CHARTS (Cont.) -726280600

TM 9-2320-364-20-1

2-14. DDEC III/IV TROUBLESHOOTING (CONT).

Section IV. TROUBLESHOOTING CHARTS (Cont.)

FLASH CODE:

DDR DISPLAY:

CHECK ENGINE LIGHT SHORT TO BATTERY (+)

SAE J1587 CODE:

SID: 239 FMI: 3

Indicates that the Check Engine Light (CEL) circuit is shorted to battery (+). This diagnostic condition is detected

when the DDEC III/IV ECM is unsuccessful in turning ON the stop engine light. This diagnostic code is typically:

(1) Failed short CEL light bulb

(2) CEL wire in vehicle harness is shorted to battery (+)

NOTE: The DDEC III/IV ECM supplies a switched ground to the check engine light circuit to turn ON the light.

FLASH CODE:

DDR DISPLAY:

CHECK ENGINE LIGHT OPEN CIRCUIT

SAE J1587 CODE:

SID: 239 FMI: 4

Indicates that the Check Engine Light (CEL) circuit is open or shorted to ground. This diagnostic condition is de-

tected when the check engine light is OFF and the DDEC III/IV ECM measures a low voltage on the check en-

gine light circuit output. This diagnostic code is typically:

(1) failed open CEL light bulb

(2) CEL wire in vehicle is open or shorted to ground

FLASH CODE:

DDR DISPLAY:

TURBO BOOST SENSOR INPUT VOLTAGE HIGH

SAE J1587 CODE:

PID: 102 FMI: 3

Indicates that the engine Turbo Boost Sensor (TBS) input to the ECM has exceeded 85% (normally > 4.25 volts)

of the sensor supply voltage. This diagnostic condition is typically:

(1) open sensor return circuit

(2) sensor signal circuit is shorted to the sensor +5 volt supply

FLASH CODE:

DDR DISPLAY:

TURBO BOOST SENSOR INPUT VOLTAGE LOW

SAE J1587 CODE:

PID: 102 FMI: 4

Indicates that the engine Turbo Boost Sensor (TBS) input to the ECM has dropped below 5% (normally < 0.25

volts) of the sensor supply voltage. This diagnostic condition is typically:

(1) open sensor signal circuit

(2) open sensor +5 volt supply circuit

(3) sensor signal is shorted to the sensor return circuit or to ground

(4) sensor +5 volt supply is shorted to sensor return circuit

FLASH CODE:

DDR DISPLAY:

OIL PRESSURE SENSOR INPUT VOLTAGE HIGH

SAE J1587 CODE:

PID: 100 FMI: 3

Indicates that the engine Oil Pressure Sensor (OPS) input to the ECM has exceeded 95% (normally > 4.75 volts)

of the sensor supply voltage. This diagnostic condition is typically:

(1) open sensor return circuit

(2) sensor signal circuit is shorted to the sensor +5 volt supply

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