VERNIER CONTROL INPUT FAILED LOW (VOLTAGE LOW) (ALSO CALLED VARIABLE SPEED GOVERNOR

TM 9-2320-364-20-1

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

Section IV. TROUBLESHOOTING CHARTS (Cont.)

E. FLASH CODE:

J1587 CODE:

P187 4 -

VERNIER CONTROL INPUT FAILED LOW (VOLTAGE LOW)

(ALSO CALLED VARIABLE SPEED GOVERNOR - VSG)

NOTE - This chart is only to be used if:

1) All basic mechanical checks and physical inspections have been performed with no problem found; and,

2) Diagnosis of DDEC III/IV was started at step START-1, pg 2-539, and you have now been referred here.

STEP/SEQUENCE

RESULT

WHAT TO DO NEXT

11-1

Multiple Code Check

Were there any other active codes

No other

Go to 11--2.

besides 187/4?

active codes.

Yes, any or all

Go to VEH5V-1 , page 2-767.

of the following active

codes: 187/3, 91/3 or 4,

100/4, 102/4, 110/4,

174/4, 175/4.

Yes - but none

Go to 11--2.

of the above.

11-2

Sensor Check

Turn ignition off.

Code 187/3 (and/or

Go to 11--6.

Disconnect vernier control

other codes).

connector.

Install a jumper wire between

sockets B and C of the vernier

Code 187/4 (and any

Go to 11--3.

harness connector.

other codes).

Turn ignition on.

Read active codes.

11-3

Check Vernier

Control Adjustment

Remove jumper and reconnect

Getting 48 to

Go to 11--5.

vernier control.

968 counts.

Hook-up DDR to the DDL

connector and select VSG

Not getting the

Go to 11--4.

CNTS.

above readings.

Push ENGINE HIGH IDLE

LATCH switch to LATCH and

release.

Read counts.

11-4

Attempt Vernier

Control Adjustment

Replace vernier control

Corrected

Go to 11-30.

(para 7-100).

problem so that Throttle

Counts is now correct.

Could not correct the

Go to 11--5.

problem.

2-617