Table 2-12. DDEC II System Code Index

TM 9-2320-364-20-1

2-11. TROUBLESHOOTING INSTRUCTIONS (CONT).

(d)

Diagnosis is built on codes that are displayed on the Diagnostic Data Reader (DDR) (Table 2-12).

Since the self-diagnostics do not detect all possible faults, the absence of a code does not mean

there are no problems in the system. If a DDEC problem is suspected (even in the absence of a

code), go to the DDEC II Troubleshooting (All Conditions) flowchart, (Para 2-13) or DDEC III/IV

Troubleshooting (All Conditions) flow chart Para 2-14. This chart can lead you to other charts

which can aid in the troubleshooting process.

(e)

If, after DDEC II or DDEC III/IV troubleshooting is completed and other symptoms remain, go to

Engine Troubleshooting.

(2)

Using the Diagnostic Data Reader (DDR).

(a)

Plug reader into truck connector and turn ENGINE switch ON.

Table 2-12. DDEC II System Code Index

Affected

Code

Sensor

Number

Description

Vernier Control

System on for 2 seconds with too low a voltage at the Vernier

Control input to the DDEC ECM.

Vernier Control

System on for 2 seconds with too high a voltage at the

Vernier Control input to the DDEC ECM.

Oil Temperature (OTS)

Engine running for 8 minutes with too high a voltage at the

OTS input to the DDEC ECM.

Oil Temperature (OTS)

Engine running for 2 seconds with too low a voltage at the

OTS input to the DDEC ECM.

Throttle Position (TPS)

System running for 2 seconds with too high a voltage at the

TPS input to the DDEC ECM.

Throttle Position (TPS)

System running for 2 seconds with too low a voltage at the

TPS input to the DDEC ECM.

Fuel Temperature (FTS)

Engine running for 8 minutes with too high a voltage at the

FTS input to the DDEC ECM.

Fuel Temperature (FTS)

Engine running for 2 seconds with too low a voltage at the

FTS input to the DDEC ECM.

NO CODES - No faults have been detected by DDEC since

the last time the codes were cleared.

ECM FAILURE - The backup system inside the DDEC ECM

has failed.

Turbo Boost (TBS)

Engine running (at less than 800 RPM or less than 30% of

maximum torque) for 5 seconds with too high a voltage at

the TBS input to the DDEC ECM.

Turbo Boost (TBS)

Engine running for 2 seconds with too low a voltage at the

TBS input to the DDEC ECM.

Oil Pressure (OPS)

Engine running for 2 seconds at less than 800 RPM with too

high a voltage at the OPS input to the DDEC ECM. Oil

temperature must be greater than 60 degrees C to log this

code.

Oil Pressure (OPS)

Engine running for 2 seconds with too low a voltage at the

OPS input to the DDEC ECM.

2-100