Compression Ignition Addict
Join Date: Feb 2008
Location: Valley Springs
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Need help diagnosing glow plugs
My service engine soon light has been on for a long time and I borrowed a generic scanner to check. Came up with codes P1391(Continuous glow plug circuit low input, bank 1), P1393(Continuous glow plug circuit low input, bank 2), and P0603(Continuous powertrain control module keep alive memory error). Not exactly sure what the last one means.
This would make sense since my truck does take a couple seconds longer to start when in gets down into the 30's. I checked the GPR and it shows 9-10 volts so it seems good, and I checked the GP's at the valve cover plug and all eight show .8-1.0 ohms. Since the GP's test good I assume the under cover harness is also good. All I can think of to check now is the continuity in the wiring harness from the GPR to the valve cover.
Is there anything I am missing? What else can I check?