1996 Ford Ranger - OBD Code P1445
HW36 CHECK PF CIRCUIT FOR SHORT TO VPWR IN HARNESS
Install breakout box, leave PCM disconnected.
Key on, engine off.
Measure resistance between PCM test pin 11 and PCM test pins 24 or 103.
Is the voltage greater than 10.5 volts?
Yes No
REPAIR short circuit. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test . REPLACE damaged PCM. RESTORE vehicle. RERUN Quick Test .
If measuring resistance, you cannot have voltage applied.
Battery Connected, Key On, PF Disconnected.
The BK/LG terminal has 5v to the sensor, Red has 12.4v, Bk/W ground.
What determines the voltage from the PCM to the PF Sensor through terminal 11? I still have the original PCM and now a Re-manufactured one with the same results.
I have completely unwrapped the wiring harness and done a thorough inspection for broken/smashed wires.
Install breakout box, leave PCM disconnected.
Key on, engine off.
Measure resistance between PCM test pin 11 and PCM test pins 24 or 103.
Is the voltage greater than 10.5 volts?
Yes No
REPAIR short circuit. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test . REPLACE damaged PCM. RESTORE vehicle. RERUN Quick Test .
If measuring resistance, you cannot have voltage applied.
Battery Connected, Key On, PF Disconnected.
The BK/LG terminal has 5v to the sensor, Red has 12.4v, Bk/W ground.
What determines the voltage from the PCM to the PF Sensor through terminal 11? I still have the original PCM and now a Re-manufactured one with the same results.
I have completely unwrapped the wiring harness and done a thorough inspection for broken/smashed wires.
I had been dogged by P1445 for several months, trying to troubleshoot this down and coming up empty. A turning point was when I used my Topdon Top Scan Lite bluetooth OBD reader to monitor the purge sensor voltage while I had the hose pulled from the canister (engine running), then putting my finger over the end of the hose to regulate how much air went in. I saw that plugging the hose made the voltage drop into range, which verified that the sensor was working properly. I then turned my attention to the purge solenoid. I researched that and found that the hose orientation actually mattered. I checked, and sure enough, the hoses were plugged in backwards. I turned it around and the code is now gone!
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carrzkiss
1983 - 2012 Ranger & B-Series
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Apr 30, 2014 10:47 PM




