R1 DIAGNOSTIC TROUBLE CODE (DTC
P0381 is set when the PCM
detects a malfunction in the glow plug warning lamp circuit.
Open WAIT TO START light
Open fuse (F-Series — Fuse 17, Econoline — Fuse 18)
Key on, engine running.
Does WAIT TO START light remain on?
GO to R2 . GO to R3 .
P1391, P1395 — RIGHT BANK AND P1393, P1396 — LEFT BANK
Note: For running KOER
glow plug monitoring self test, refer to Section 2C .
One of the above codes will set when glow plugs are commanded on for over 35 seconds and battery voltage is between 11.8v and 14v, with at least one glow plug not being powered.
Measure voltage between large wire terminal Circuit 38 (BK/O) on glow plug relay and battery ground.
Is battery voltage present?
GO to S2 . SERVICE open in Circuit 38 (BK/O) or fusible links.
AH1 CONTINUOUS DTC P0603
IS SET WHEN THE PCM
HAS LOST KAPWR
Note: This code may have been caused by disconnecting the PCM
or the batteries.
Battery or PCM
has been disconnected.
Battery cables loose or poor connection.
Open in KAPWR circuit.
Check for other codes.
Key on, engine off.
Cycle key off, then on.
Perform Retrieve Continuous DTCs.
Was DTC P0603
GO to AH2 . Intermittent failure, unable to duplicate. REPAIR other DTCs as necessary. If none, testing is complete. RESTORE vehicle. CLEAR DTCs and RETEST.