TROUBLESHOOTING CHARTS (Cont.) -726280602

TM 9-2320-364-20-1

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

Section IV. TROUBLESHOOTING CHARTS (Cont.)

FLASH CODE:

DDR DISPLAY:

ECM A/D CONVERSION FAILURE

SAE J1587 CODE:

SID: 254 FMI: 12

Indicates that the DDEC III/IV ECMs internal Analog to Digital (A/D) Convertor device has malfunctioned. Inter-

mittent diagnostic conditions of this type can be caused by faulty external electrical system.

FLASH CODE:

DDR DISPLAY:

NONVOLATILE MEMORY DATA INCORRECT

SAE J1587 CODE:

SID: 253 FMI: 2

Indicates that the ECM upon startup has been unable to read a valid copy of a engine data record (calibration,

faults, or accumulators) stored in nonvolatile memory.

FLASH CODE:

DDR DISPLAY:

NONVOLATILE MEMORY FAILURE

SAE J1587 CODE:

SID: 253 FMI: 12

Indicates that the ECM was unable to update an engine data record (calibration, faults, or accumulators) stored in

nonvolatile memory.

FLASH CODE:

DDR DISPLAY:

J1587 DATA LINK FAILURE

SAE J1587 CODE:

SID: 250 FMI: 12

Indicates that the J1587 (diagnostic) data link is no longer allowing the ECM to transmit data. This diagnostic

condition is typically:

(1)

either or both of the data link circuits are open at some point in the network

(2)

either or both of the data link circuits are shorted to ground at some point in the network

(3)

either or both of the data link circuits are shorted to battery (+) at some point in the network

(4)

the pair of data link circuits are shorted together

FLASH CODE:

DDR DISPLAY:

XXX INJECTOR RESPONSE TIME LONG

SAE J1587 CODE:

SID: XX FMI: 0

Indicates that the time it takes from when the DDEC III/IV ECM requests an injector be turned on to when the in-

jector solenoid valve actually closes is longer than the high limit of the expected range. This diagnostic condition

is typically:

(1)

bad injector harness/connection (high resistance)

(2)

blown fuses in the ECM battery (+) voltage supply harness

(3)

sticky solenoid valve

NOTE: The injector diagnostic SID (Subsystem Identifier) indicates which cylinder number has an injector with a

long response time. The injector number describes the cylinder and/or bank which has the injector with a

long response time.

Injector response times generally increase with low battery supply voltage and decrease with high battery

supply voltage. Although injector response times vary from injector to injector at a given RPM, each indi-

vidual injector response time should remain relatively consistent from one firing to the next. Wide varia-

tions in response time (typically +/-- 0.2 msec) for one injector at a steady engine RPM may indicate an

electrical problem (faulty alternator or voltage regulator, poor or broken ground cables, etc.).

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