VEH5V - VEHICLE HARNESS +5 VOLTS SUPPLY

TM 9-2320-364-20-1

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

Section IV. TROUBLESHOOTING CHARTS (Cont.)

E. VEH5V - VEHICLE HARNESS +5 VOLTS SUPPLY

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

VEH5V-1

Check for Low

Battery Voltage

Was there also a Code 168/1?

Yes.

Go to 46-1 (page 2-719).

No.

Go to VEH5V-2.

VEH5V-2

Check for +5 Volts

at TPS

Turn ignition off.

Less than

Go to VEH5V-3.

Disconnect the Throttle Position

4.7 volts.

Sensor (TPS) connector.

Turn ignition on.

Greater than

Go to VEH5V-11.

Read voltage on the TPS

5.2 volts.

connector, pin C (red lead) to pin

A (black lead).

Between 4.7

Go to VEH5V-8.

and 5.2 volts.

VEH5V-3

Check for +5 Volts

or Return Open

Turn ignition off.

Less than

Go to VEH5V-4.

Disconnect the vehicle harness

or equal to 5 ohms.

connector at the ECM.

Install a jumper wire between pins

Greater than

Either the engine +5 volt line

A and C of the TPS connector.

5 ohms or open.

(ckt #916) or the sensor return

Read resistance between sockets

line (ckt #952) is open. Repair

A3 and C3 of the vehicle harness

open. Then go to VEH5V-30.

connector.

2-767