P187 4 - VERNIER CONTROL INPUT FAILED HIGH (HIGH VOLTAGE) (ALSO CALLED VARIABLE SPEED GOVERNOR

TM 9-2320-364-20-1

Section IV. TROUBLESHOOTING CHARTS (Cont.)

E. FLASH CODE:

J1587 CODE:

P187 3 - VERNIER CONTROL INPUT FAILED HIGH (HIGH VOLTAGE)

(ALSO CALLED VARIABLE SPEED GOVERNOR - VSG)

STEP/SEQUENCE

RESULT

WHAT TO DO NEXT

12-5

Check for Short to

+5 Volt Line

Connect all connectors to ECM.

Greater than 1.0 volts.

Signal line (ckt #510 or #1525)

Turn ignition on.

is shorted to the vehicle +5 volt

Read voltage on vernier control

line (ckt #916) or another

harness connector pin B (1525)

voltage source. Repair short.

to pin A (952).

Then go to 12-30.

Less than or equal

Go to 12-7.

to 1.0 volts.

12-7

Check ECM

Connectors

Disconnect the vehicle harness

Terminals and

Replace ECM (para 7-57).

connector.

connectors are okay.

Then go to 12-30.

Check terminals at the

vehicle harness connector (both

Problem found.

Repair terminals/connectors

ECM and harness side) for

(para 7-101). Then go to 12-30.

damage; bent, corroded, and

unseated pins or sockets.

2-627