Code
P1002
Generic
P — Powertrain
Fuel Volume Regulator Control Circuit/Open
Views:
UK: 2
EN: 3
RU: 0
AI status
Completed
Completed
100%
Causes
- Open, broken or disconnected wire in regulator control circuit
- Corroded or damaged connector at the fuel volume regulator
- Failed fuel volume regulator (open coil/solenoid)
- Blown fuse or faulty relay providing power to regulator circuit
- High resistance in supply or ground circuit
- PCM output driver fault
Symptoms
- MIL (check engine light) illuminated
- Reduced engine power or limp-home mode
- Hard starting or no-start condition
- Rough idle, misfire, or stalling
- Possible increased fuel consumption or poor drivability
What to check
- Scan for stored and pending codes; read freeze frame and related fuel system codes
- Visual inspection of wiring harness and connectors at the regulator and PCM
- Check fuses and relays for the fuel/regulator circuit
- Backprobe regulator connector to verify supply voltage and control signal with key on and while cranking/running
- Measure regulator coil continuity and resistance against manufacturer spec
- Wiggle test harness while engine/ignition is operating to reproduce fault
Signal parameters
- Supply voltage at regulator: ~battery voltage with key ON (exact value per vehicle)
- Control signal from PCM: either switched ground or PWM duty-cycle (varies by application)
- Regulator coil resistance: specified by manufacturer (typically a few ohms to several tens of ohms)
- Control waveform: steady ground or pulsed output when PCM commands fuel volume changes; frequency and duty vary by design
Diagnostic algorithm
- Retrieve P1002 and any related codes. Note freeze-frame data and test drive conditions.
- Perform a visual check of connectors, wiring, and harness for damage, corrosion, pins pushed out, or signs of water intrusion.
- Verify fuses and relays that supply the regulator circuit. Replace any blown fuses and retest.
- With the ignition ON (engine off), backprobe the regulator connector: check for battery voltage on the power terminal and good ground reference on ground terminal.
- Measure the regulator coil resistance between the regulator control pin and ground. Compare to manufacturer specification; open/infinite resistance indicates a failed coil.
- Start or crank engine and monitor the PCM control signal at the regulator: use a digital multimeter for basic presence or an oscilloscope/graphing scanner to observe PWM/ground switching. No control signal indicates open circuit or PCM output failure.
- If supply and control wiring are good but regulator shows open coil, replace the fuel volume regulator and retest.
- If regulator is good but no control signal from PCM, trace wiring back to PCM looking for opens/shorts. Repair wiring or connector faults.
- If wiring and regulator are OK but command still absent, consider PCM driver fault—confirm with manufacturer diagnostic procedures before replacing PCM.
- Clear codes and perform test drive to verify repair. Monitor for reappearance of fault and check for related fuel system codes.
Likely causes
- Damaged/loose connector at the fuel volume regulator
- Open or shorted control wire between PCM and regulator
- Defective fuel volume regulator solenoid (coil open)
- Blown fuse or failed fuel system relay
Fault status
Status
PCM detected an open or interrupted control circuit for the fuel volume regulator and set DTC P1002. The MIL may be illuminated and the vehicle may enter reduced power or limp mode until the fault is corrected. The code should be confirmed by inspecting wiring, connectors, fuse/relay and testing the regulator and PCM output.
Repair difficulty: Medium
Diagnostic time: 0.5-3.0 hours
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Code
P1002
SAAB
P — Powertrain
EVAP Purge Valve, Output From Control Module High
Views:
UK: 4
EN: 10
RU: 6
AI status
Completed
Completed
100%
Causes
- Open, broken or disconnected wire in regulator control circuit
- Corroded or damaged connector at the fuel volume regulator
- Failed fuel volume regulator (open coil/solenoid)
- Blown fuse or faulty relay providing power to regulator circuit
- High resistance in supply or ground circuit
- PCM output driver fault
Symptoms
- MIL (check engine light) illuminated
- Reduced engine power or limp-home mode
- Hard starting or no-start condition
- Rough idle, misfire, or stalling
- Possible increased fuel consumption or poor drivability
What to check
- Scan for stored and pending codes; read freeze frame and related fuel system codes
- Visual inspection of wiring harness and connectors at the regulator and PCM
- Check fuses and relays for the fuel/regulator circuit
- Backprobe regulator connector to verify supply voltage and control signal with key on and while cranking/running
- Measure regulator coil continuity and resistance against manufacturer spec
- Wiggle test harness while engine/ignition is operating to reproduce fault
Signal parameters
- Supply voltage at regulator: ~battery voltage with key ON (exact value per vehicle)
- Control signal from PCM: either switched ground or PWM duty-cycle (varies by application)
- Regulator coil resistance: specified by manufacturer (typically a few ohms to several tens of ohms)
- Control waveform: steady ground or pulsed output when PCM commands fuel volume changes; frequency and duty vary by design
Diagnostic algorithm
- Retrieve P1002 and any related codes. Note freeze-frame data and test drive conditions.
- Perform a visual check of connectors, wiring, and harness for damage, corrosion, pins pushed out, or signs of water intrusion.
- Verify fuses and relays that supply the regulator circuit. Replace any blown fuses and retest.
- With the ignition ON (engine off), backprobe the regulator connector: check for battery voltage on the power terminal and good ground reference on ground terminal.
- Measure the regulator coil resistance between the regulator control pin and ground. Compare to manufacturer specification; open/infinite resistance indicates a failed coil.
- Start or crank engine and monitor the PCM control signal at the regulator: use a digital multimeter for basic presence or an oscilloscope/graphing scanner to observe PWM/ground switching. No control signal indicates open circuit or PCM output failure.
- If supply and control wiring are good but regulator shows open coil, replace the fuel volume regulator and retest.
- If regulator is good but no control signal from PCM, trace wiring back to PCM looking for opens/shorts. Repair wiring or connector faults.
- If wiring and regulator are OK but command still absent, consider PCM driver fault—confirm with manufacturer diagnostic procedures before replacing PCM.
- Clear codes and perform test drive to verify repair. Monitor for reappearance of fault and check for related fuel system codes.
Likely causes
- Damaged/loose connector at the fuel volume regulator
- Open or shorted control wire between PCM and regulator
- Defective fuel volume regulator solenoid (coil open)
- Blown fuse or failed fuel system relay
Fault status
Status
PCM detected an open or interrupted control circuit for the fuel volume regulator and set DTC P1002. The MIL may be illuminated and the vehicle may enter reduced power or limp mode until the fault is corrected. The code should be confirmed by inspecting wiring, connectors, fuse/relay and testing the regulator and PCM output.
Repair difficulty: Medium
Diagnostic time: 0.5-3.0 hours
Similar codes
Your experience will help others
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