Vehicle Battery

1996 PCED OBDI

SECTION 18: Diesel Diagnosis — 7.3L DI Engine

A: Vehicle Battery

A1 DIAGNOSTIC TROUBLE CODES (DTCs) 0563/0562/0560: CHECK BATTERY VOLTAGE

Key on, engine off.
Measure voltage across battery terminals.

Is voltage greater than 9.5 volts?

Note: DTC 0563 may be a temporary condition with a 24 volt jump start. DTC 0562 may be a temporary condition at crank only.

0563 — System voltage high

0562 — System voltage low

0560 — System voltage malfunction

Yes	No
F-Series, GO to A2. Econoline, GO to A12.	SERVICE discharged battery. REFER to Section 14-00 in Body, Chassis Service Manual.

A2 CHECK VOLTAGE AT MAXI FUSE 9

Measure voltage between maxi fuse 9 at power distribution box to battery negative post.

Is battery voltage present?

Yes	No
GO to A3.	REPAIR open in Circuit 37 (Y) between the power distribution box and the starter relay.

A3 CHECK MAXI FUSE 9

Check maxi fuse 9 power distribution box.

Is fuse blown?

Yes	No
REPAIR short to ground and REPLACE maxi fuse 9.	GO to A4.

A4 CHECK CIRCUIT 37 (Y) TO RELAY

Key off.
Remove PCM relay.
Remove maxi fuse 9.
Measure resistance between the nonpower side of the maxi fuse 9 to Circuit 37 (Y) of the PCM relay connector.

Is resistance less than 5 ohms?

Yes	No
GO to A5.	REPAIR open in Circuit 37 (Y) between fuse and relay connector.

A5 CHECK IGNITION FEED TO DIODE

Remove diode from power distribution box.
Key on.
Measure voltage from battery ground to ignition feed side of diode connector.

Is battery voltage present?

Yes	No
GO to A6.	REPAIR open in ignition feed Circuit 16 (R/LG) or ignition switch.

A6 CHECK DIODE

Key off.
Disconnect diode.

Does diode check OK?

Yes	No
F-Series, GO to A7. Econoline, GO to A13.	REPLACE diode.

A7 CHECK CIRCUIT 175 (BK/Y)

Measure resistance between nonpower side of diode connector Circuit 175 (BK/Y) to PCM relay connector.

Is resistance less than 5 ohms?

Yes	No
GO to A8.	REPAIR open in Circuit 175.

A8 CHECK GROUND CIRCUIT 57 (BK) AT RELAY

Key off.
Measure resistance between battery negative to Circuit 57 (BK) at PCM relay connector.

Is resistance less than 5 ohms?

Yes	No
GO to A9.	REPAIR open in Circuit 57 (BK).

A9 CHECK CIRCUIT 361 (R) FROM RELAY TO PCM

Disconnect PCM and inspect for damaged or pushed-out pins, corrosion, loose wires, etc. Service as necessary.
Measure resistance between Circuit 361 (R) at PCM relay connector to Test Pins 71 and 97.

Is resistance less than 5 ohms?

Yes	No
GO to A10.	REPAIR open in Circuit 361 (R) between relay and PCM.

A10 CHECK PWR GND CIRCUIT CONTINUITY

Key off.
Install breakout box. Leave PCM disconnected. Inspect for damaged or pushed-out pins.
Measure resistance between battery negative post and Test Pins 25, 51, 76, 77 and 103 at the breakout box.

Is each resistance less than 5.0 ohms?

Yes	No
F-Series, GO to A11. Econoline, GO to A14.	SERVICE open in PWR GND circuit. REMOVE breakout box. RECONNECT PCM. RERUN Scan Tool Diagnostic Test.

A11 CHECK PCM RELAY

Key off.
Disconnect maxi fuse 9.
Install PCM relay.
Breakout box install, PCM disconnected.
Key on, engine off.
Measure resistance between nonpower side of maxi fuse 9 to Test Pins 71 and 97.

Is resistance less than 5 ohms?

Yes	No
If fault is still present, REPLACE PCM.	REPLACE PCM relay.

A12 CHECK VOLTAGE AT PCM RELAY

Key off.
Remove PCM relay from power distribution box.
Measure voltage at PCM relay connector Circuit 37 (Y) to battery negative.

Is battery voltage present?

Yes	No
GO to A5.	REPAIR open in Circuit 37 (Y) between PCM relay and starter relay.

A13 CHECK CIRCUIT 16

Key off.
Measure resistance between nonpower side of diode connector Circuit 16 (R/LG) to PCM relay connector.

Is resistance less than 5 ohms?

Yes	No
GO to A8.	REPAIR open in Circuit 16 (R/LG) between diode and relay.

A14 CHECK PCM RELAY

Key off.
Breakout box installed.
PCM disconnected.
PCM relay installed.
Key on.
Measure voltage between battery negative post to Test Pins 71 and 97.

Is battery voltage present?

Yes	No
If fault is still present, REPLACE PCM.	REPLACE PCM relay.