TROUBLESHOOTING CHARTS (Cont.) -726280599

TM 9-2320-364-20-1

Section IV. TROUBLESHOOTING CHARTS (Cont.)

FLASH CODE:

DDR DISPLAY:

THROTTLE SENSOR INPUT VOLTAGE LOW

SAE J1587 CODE:

PID: 91 FMI: 4

Indicates that the Throttle Position Sensor (TPS) 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 sensor return circuit or to ground

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

FLASH CODE:

DDR DISPLAY:

FUEL TEMP SENSOR INPUT VOLTAGE HIGH

SAE J1587 CODE:

PID: 174 FMI: 3

Indicates that the engine Fuel Temperature Sensor (FTS) input to the ECM has exceeded 95% (normally > 4.75

volts) of the sensor supply voltage. NOTE: This code will only be logged during warm engine operation. This

diagnostic condition is typically:

(1) open sensor signal circuit

(2) open sensor return circuit

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

FLASH CODE:

DDR DISPLAY:

FUEL TEMP SENSOR INPUT VOLTAGE LOW

SAE J1587 CODE:

PID: 174 FMI: 4

Indicates that the engine Fuel Temperature Sensor (FTS) input to the ECM has dropped below 5% (normally

< 0.25 volts) of the sensor supply voltage. This diagnostic condition is typically:

(1) sensor signal circuit is shorted to sensor return or to ground

(2) sensor +5 volt supply is shorted to sensor return circuit or to ground

FLASH CODE:

DDR DISPLAY:

CHECK GAUGES LIGHT SHORT TO BATTERY (+)

SAE J1587 CODE:

SID: 238 FMI: 3

Indicates that the Check Gauges Light (CGL) 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 CGL light bulb

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

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

FLASH CODE:

DDR DISPLAY:

CHECK GAUGES LIGHT OPEN CIRCUIT

SAE J1587 CODE:

SID: 238 FMI: 4

Indicates that the Check Gauges Light (CGL) circuit is open or shorted to ground. This diagnostic condition is

detected when the stop engine light is OFF and the DDEC III/IV ECM measures a low voltage on the stop engine

light circuit output. This diagnostic code is typically:

(1) failed open CGL light bulb

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

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