2003 GMC Envoy code P1345 took it to Firestone, crankshaft position sensor had it replace. Drove over a 140 miles no engine light. Cranked next day the engine light came back on code reads P1345 ?

SOURCE: check engine light on - 2003 gmc envoy XL

That code represents a lower than expected reading for temperature (coolant). First thing to do is check your coolant level, as if it is low, then the sensor can not read correctly. Second, you may have a thermostat that is stuck open, allowing the coolant to cool off too much. The sensor should be mounted on top of the engine, near the thermostat housing.

SOURCE: 99 Gmc Suburban

On the 1999 - 2000 5.7 vortec engines the distributor gears wear causing the timing to change 2 or more degrees. The ecm is designed to shut down at 2 or more degreedifference. This is in a GM bulletin that recommends replacement at 160k miles. Mine went out at 150k miles. Very similar driving symtoms until it quit running. Both cam sensor codes were set on mine though, not the crank sensor.

SOURCE: Crankshaft and camshaft position sensors

MAke sure you replaced the right sensor and it's the proper design.(If you bought a generic part, it;s probably the wrong thing) I replaced my cam and crank sensors with the generic ones from AutoZone and they had no effect. Took it to Nissan, they replaced both at my expense, AND REPROGRAMMED THE ECU. That fixed that problem SES light hasn;t come on in 6 months....Fingers crossed

Ronny Bennett Sr.

• 6988 Answers
• Posted on Jan 19, 2010

SOURCE: engine code p1345 on 97 Z-71

Most likely the timing has jumped,or the cam sensor is bad.

SOURCE: 2003 GMC Sonoma 81000 miles

CODE PO155 - HO2S 21 BANK 2 SENSOR 1 HEATER CIRCUIT MALFUNCTION CONDITIONS.CHECK O2 SENSOR FUSE AND WIRING CRCUIT BEFORE BUYING A NEW HO2S.IF SENSOR BAD REPLACE IT.THEN YOU CAN CLEAR THE CODE.