Focus Fanatics - View Single Post - DTC Codes (Detailed Descriptions)
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Old 09-14-2005, 03:34 PM   #5
S2
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P1409 - EGR Vacuum Regulator Solenoid Circuit Malfunction This test checks the electrical function of the EGRVR solenoid. The test fails when the EGRVR circuit voltage is either too high or too low when compared to the expected voltage range. The EGR system must be enabled for the test to be completed. EGRVR circuit open
VPWR open to EGRVR solenoid
EGRVR circuit short to VPWR or GND
Damaged EGRVR solenoid
Damaged PCM
The EGR vacuum regulator solenoid resistance is from 26 to 40 ohms.

P1411 - Secondary Air Injection (AIR) system downstream flow The secondary air injection system does not detect the presence of air in the exhaust when introduced by the secondary air injection system Electric AIR Pump
Hose from AIR pump leak
AIR bypass solenoid leak/blocked
Hose from AIR pump blocked
AIR bypass solenoid stuck open/closed
In order to test the AIR pump, it must be capable of driving the HO2S lean.

P1413 Secondary Air Injection System Monitor Circuit Low The secondary air injection system monitor circuit is low, indicating the electrical AIR pump is off although the electrical AIR pump was commanded on by the PCM. Open B+ circuit
Open AIR circuit
Damaged PCM
Air circuit short to ground
Damaged AIR pump
Damaged solid state relay
The AIR monitor circuit is held low by the resistance path through the AIR pump when the pump is off. Also, look for open circuit from SSR to AIR pump.

P1414 Secondary Air Injuction System Monitor Circuit High The secondary air injection system monitor circuit is high, indicating the electrical AIR pump is on although the electrical AIR pump was commanded off by the PCM. Open AIR monitor circuit from the pump
AIR circuit short to power
Damaged solid state relay
Open AIR pump ground
Damaged AIR pump
Damaged PCM

P1432 - Thermostat Heater Control (THTRC) Circuit Failure The Comprehensive component monitor (CCM) monitors the THTRC circuit to the PCM for high and low voltage. If during testing; voltage was to fall below a calibrated limit for a calibrated amount of time the test will fail and set the DTC and MIL. Open or shorted THTRC circuit
Open VPWR
Open or shorted thermostat assembly
Damaged PCM
DTC P1432 is a THTRC circuit check. Testing should include wire harness, thermostat heater and PCM.

P1443 - Very Small Or No Purge Flow Condition A fuel tank pressure change greater than a minus (-) 7 inches of H 2 O in 30 seconds has occurred with purge (fuel vapor) flow less than 0.02 pounds per minute. Blocked fuel vapor hose between EVAP canister purge valve and FTP sensor.
Blocked fuel vapor hose between EVAP canister purge valve and engine intake manifold.
Blocked vacuum hose between EVAP canister purge valve-solenoid and engine intake manifold.
EVAP canister purge valve stuck closed (mechanically).
Check for blockages between the fuel tank, EVAP canister purge valve and engine intake manifold. Check obstructions in the EVAP canister purge valve diaphragm and ports.

P1450 - Unable to Bleed Up Fuel Tank Vacuum Monitors the fuel vapor vacuum and pressure in the fuel tank. The system failure occurs when the EVAP running loss monitor detects excessive fuel tank vacuum with the engine running (but not at idle). Blockages or kinks in EVAP canister tube or EVAP canister purge outlet tube (between fuel tank, EVAP canister purge valve and EVAP canister)
Fuel filler cap stuck closed (no vacuum relief)
Contaminated fuel vapor elbow on EVAP canister
Restricted EVAP canister
CV solenoid stuck open (partially or fully)
Plugged CV solenoid filter
EVAP canister purge valve stuck open
VREF circuit open (harness near FTP sensor, FTP sensor or PCM)
Damaged FTP sensor

P1451 - EVAP Control System Canister Vent Solenoid Circuit Malfunction
Monitors the canister vent (CV) solenoid circuit for an electrical failure. The test fails when the signal moves outside the minimum or maximum allowable calibrated parameters for a specified canister vent duty cycle by PCM command. VPWR circuit open
CV solenoid circuit shorted to PWR GND or CHASSIS GND
Damaged CV solenoid
CV solenoid circuit open
CV solenoid circuit shorted to VPWR
Damaged PCM
To verify normal function, monitor the EVAP canister vent solenoid signal PID EVAPCV and the signal voltage (PCM control side). With the valve open, EVAPCV will indicate 0 percent duty cycle and the voltage approximately equal to battery voltage. When the valve is commanded fully closed, EVAPCV will indicate 100% duty cycle and a voltage drop of 4 volts minimum is normal. Output test mode may be used to switch output ON/OFF to verify function.

P1460 - Wide Open Throttle A/C Cutout Primary Circuit Malfunction NOTE: For applications that use a normally open relay to control the A/C clutch, the following description applies to the A/C clutch relay control circuit. Monitors the wide open throttle A/C cutoff (WAC) circuit output from the PCM. The test fails if: When the PCM grounds the WAC circuit, excessive current draw is detected on the WAC circuit; or with the WAC circuit not grounded by the PCM, voltage is not detected on the WAC circuit (the PCM expects to detect VPWR voltage coming through the WAC relay coil to the WAC circuit). Open or shorted WAC circuit
Damaged WAC relay (or CCRM)
Open VPWR circuit to WAC relay
Damaged PCM
When the WACF PID reads YES, a fault is currently present
An open circuit or short to ground can only be detected when the PCM is not grounding the circuit
A short to power can only be detected when the PCM is grounding the circuit
During KOEO and KOER self-test, the WAC circuit will be cycled ON and OFF
Verify A/C and defrost were OFF during KOEO and KOER self-test (Check ACCS PID to verify)
If vehicle is not equipped with A/C, DTC P1460 can be ignored

P1461 - Air Conditioning Pressure Sensor (ACP) Sensor High Voltage Detected ACP inputs a voltage to the PCM. If the voltage is above a calibrated level the DTC will set. ACP sensor circuit short to PWR
ACP circuit open
Damaged PCM
ACP circuit short to VREF
ACP circuit short to SIGRTN
Damaged ACP sensor
Verify VREF voltage between 4.0 and 6.0V.

P1462 - Air Conditioning Pressure Sensor (ACP) Sensor Low Voltage Detected ACP inputs a voltage to the PCM. If the voltage is below the calibrated level the DTC will set. ACP circuit short to GND or SIGRTN
VREF circuit open
Damaged PCM
Open ACP circuit
Damaged ACP sensor
Verify VREF voltage between 4.0 and 6.0V.

P1463 - Air Conditioning Pressure Sensor (ACP) Insufficient Pressure Change Each time the A/C clutch engages, the PCM is looking for a pressure change in the refrigerant. If the change in pressure is outside of the calibration the DTC will set. A/C system mechanical failure
Open ACP or VREF circuit
A/C sensor damaged
A/C system electrical failure
A/C clutch always engaged
Verify A/C system function, including refrigerant charge.

P1464 - A/C Demand Out Of Self-Test Range Indicates the ACCS input to the PCM was high during Self-Test. A/C was on during self-test
A/C Clutch PWR circuit short to power (applications with N/C WAC relay contacts)
ACCS circuit short to power
Damaged A/C demand switch
Damaged WAC relay (or CCRM)
Damaged PCM
If A/C or defrost were on during self-test, turn off and rerun test.

P1469 - Low A/C Cycling Period Indicates frequent A/C compressor clutch cycling. Mechanical A/C system concern (such as low refrigerant charge, damaged A/C cycling switch)
Intermittent open between the cycling pressure switch and pin 41 (ACCS) to the PCM
Intermittent open in IGN RUN circuit to cycling pressure switch (if applicable)
An intermittent open circuit, although possible, is unlikely
This test was designed to protect the transmission. In some strategies, the PCM will unlock the torque converter during A/C clutch engagement. If a concern is present that results in frequent A/C clutch cycling, damage could occur if the torque converter was cycled at these intervals. This test will detect this condition, set the DTC and prevent the torque converter from excessive cycling.

P1474 - Low Fan Control (LFC) Primary Circuit Failure Monitors the low fan control (LFC) (fan control [FC] for one speed fan application) primary circuit output from the PCM. The test fails if: When the PCM grounds the LFC/FC circuit, excessive current draw is detected on the LFC/FC circuit; or with the LFC/FC circuit not grounded by the PCM, voltage is not detected on the LFC/FC circuit (the PCM expects to detect VPWR voltage coming through the low speed FC relay [or CCRM] coil to the LFC/FC circuit). Open or shorted LFC/FC circuit
Open VPWR circuit to low speed FC relay
Damaged low speed FC relay (or CCRM)
Damaged PCM
When the LFCF PID reads YES, a fault is currently present
An open circuit or short to ground can only be detected when the PCM is not grounding the LFC/FC circuit
A short to power can only be detected when the PCM is grounding the LFC/FC circuit.
During KOEO and KOER Self-Test, the LFC/FC circuit will be cycled on and off

P1474 - Hydraulic Cooling Fan Primary Circuit Failure (HCF) This test checks the electrical function of the (HCF) primary circuit. The test fails if: the PCM detects voltage either too high or too low when compared to the expected voltage range on the (HCF) primary circuit. HCF circuit open
HCF circuit short to power
HCF circuit short to ground
Damaged HCF solenoid
Damaged PCM
The HCF solenoid is integrated in the HCF pump which looks like a power steering pump. The electrical resistance of the solenoid windings is nominally 10 ohms.

P1477 - Medium Fan Control (MFC) Primary Circuit Failure Monitors the medium fan control (MFC) primary circuit output from the PCM. The test fails if: With the MFC output commanded on (grounded), excessive current draw is detected on the MFC circuit; or with the MFC circuit commanded off, voltage is not detected on the MFC circuit (the PCM expects to detect IGN START/RUN voltage coming through the medium speed FC relay coil to the MFC circuit). Open or shorted MFC circuit
Open IGN START/RUN circuit to medium speed FC relay
Damaged medium speed FC relay
Damaged PCM
Same as P1479, except with MFC circuit and MFCF PID (for early build Escape, MFCF and MFC PIDs may not be available)
Using Output Test Mode on scan tool, when commanding the low speed fan on, the PCM will also activate the medium speed fan output.

P1479 - High Fan Control (HFC) Primary Circuit Failure Monitors the high fan control (HFC) primary circuit output from the PCM. The test fails if: With the HFC output commanded on (grounded), excessive current draw is detected on the HFC circuit; or with the HFC circuit commanded off, voltage is not detected on the HFC circuit (the PCM expects to detect VPWR voltage coming through the high speed FC relay [or CCRM] coil to the HFC circuit). Open or shorted HFC circuit
Open VPWR circuit to high speed FC relay
Damaged high speed FC relay (or CCRM)
Damaged PCM
When the HFCF PID reads YES, a fault is currently present
An open circuit or short to ground can only be detected when the PCM is not grounding the HFC circuit
A short to power can only be detected when the PCM is grounding the HFC circuit
During KOEO and KOER self-test, the HFC circuit will be cycled on and off

P1500 - Vehicle Speed Sensor (VSS) Intermittent Indicates the VSS input signal was intermittent. This DTC is set when a VSS fault interferes with other OBDII tests, such as Catalyst efficiency monitor, EVAP monitor, HO2S monitor, etc. Intermittent VSS connections
Intermittent open in VSS harness circuit(s)
Intermittent short in VSS harness circuit(s)
Damaged VSS
Damaged PCM

P1501 - Vehicle Speed Sensor (VSS) Out of Self Test Range Indicates the VSS input signal is out of Self Test range. If the PCM detects a VSS input signal any time during Self Test, a DTC P1501 will be set and the test will abort. Noisy VSS input signal from Radio Frequency Interference/ Electro-Magnetic Interference (RFI/EMI) external sources such as ignition wires, charging circuit or after market equipment.
Check for VSS input to be 0 mph when vehicle transmission is in Park.

P1502 - Vehicle Speed Sensor (VSS) Intermittent Indicates the powertrain control module (PCM) detected an error in the vehicle speed information. Vehicle speed data is received from either the vehicle speed sensor (VSS), transfer case speed sensor (TCSS), anti-lock brake system (ABS) control module, generic electronic module (GEM), or central timer module (CTM). This DTC is set the same way as P0500. However, it is intended to flash the transmission control indicator lamp (TCIL) for first time VSS circuit error/malfunctions. Refer to possible causes for P0500.
Refer to diagnostic aids for P0500.

P1502 - Vehicle Speed Sensor (VSS) Intermittent (TCIL illuminates) Indicates the powertrain control module (PCM) detected an error in the vehicle speed information. Vehicle speed data is received from either the vehicle speed sensor (VSS), anti-lock brake system (ABS) control module, generic electronic module (GEM), or central timer module (CTM). This DTC is set the same way as P0500. However, it is intended to flash the transmission control indicator lamp (TCIL) for first time VSS circuit error/malfunctions. Refer to possible causes for P0500 Refer to diagnostic aides for P0500

P1504 - Idle Air Control (IAC) Circuit Malfunction This DTC is set when the PCM detects an electrical load failure on the IAC output circuit. IAC circuit open
VPWR to IAC solenoid open
IAC circuit short to PWR
IAC circuit short to GND
Damaged IAC valve
Damaged PCM
The IAC solenoid resistance is from 6 to 13 ohms.

P1506 - Idle Air Control (IAC) Overspeed Error This DTC is set when the PCM detects engine idle speed that is greater than the desired rpm. IAC circuit short to GND
Damaged IAC valve
IAC valve stuck open
Vacuum leaks
Failed EVAP system
Damaged PCM
Disconnect IAC valve and look for little or no change in engine rpm as an indication of a stuck or damaged valve.

P1507 - Idle Air Control (IAC) Underspeed Error This DTC is set when the PCM detects engine idle speed that is less than the desired rpm. IAC circuit open
IAC circuit short to PWR
VPWR to IAC solenoid open
Air inlet is plugged
Damaged IAC solenoid
Damaged PCM
The IAC solenoid resistance is from 6 to 13 ohms
Disconnect IAC valve and look for no change in engine rpm as an indication of a stuck or damaged valve

P1516 - Intake Manifold Runner Control Input Error (Bank 1)
P1517 - Intake Manifold Runner Control Input Error (Bank 2) The IMRC system is monitored for failure during continuous or key ON engine OFF self-test. Each DTC will distinguish the corresponding failed bank for IMRC actuator assemblies with dual monitor switches. The test fails when the signal on the monitor pin is outside an expected calibrated range. Mechanical concern - bind, seize, damage or obstruction of IMRC hardware
An IMRCM PID reading at closed throttle that is less than VREF may indicate a fault
An IMRCM PID reading near 1 volt or greater with engine rpm of at least 3000 may indicate a fault

P1518 - Intake Manifold Runner Control Malfunction (Stuck Open) The IMRC system is monitored for failure during continuous, key ON engine OFF or key ON engine running self-test. The test fails when the signal on the monitor pin is less than an expected calibrated range at closed throttle. IMRC monitor signal circuit shorted to PWR GND or SIG RTN
Damaged IMRC actuator
Damaged PCM
An IMRCM PID reading approximately near 1 volt at closed throttle may indicate a fault

P1519 - Inlet Manifold Runner Control Malfunction (Stuck Closed) The IMRC system is monitored for failure during continuous, key ON engine OFF or key ON engine running self-test. The test fails when the signal on the monitor pin is more than an expected calibrated range with IMRC activated. IMRC monitor circuit open
IMRC control circuit open
IMRC monitor circuit short to VREF
IMRC monitor return circuit open
Damaged IMRC actuator
IMRC VPWR circuit open
Damaged PCM
An IMRCM PID reading at VREF with engine rpm of at least 3000 may indicate a fault.

P1549 - Intake Manifold Communication Control Circuit Malfunction The IMCC or intake manifold tuning (IMT) valve system is monitored for failure during continuous or key ON engine OFF self-test. The test fails when the PCM detects a concern with IMT valve output circuit. Open IMT valve circuit
Open VPWR circuit
Shorted IMT valve circuit
Damaged IMT valve
Damaged PCM
An IMT valve fault PID (IMTVF) displaying YES status may indicate a fault

P1550 - Power Steering Pressure (PSP) Sensor Malfunction The PSP sensor input signal to PCM is continuously monitored. The test fails when the signal falls out of a maximum or minimum calibrated range. PSP sensor damaged
Damaged PCM
The DTC indicates the PSP sensor is out of Self-Test range.

P1572 - Brake Pedal Switch Circuit Indicates that the brake input rationality test for brake pedal position (BPP) and brake pressure applied (BPA) switches has failed. One or both inputs to the PCM did not change when it was expected to. Misadjusted brake switch
Blown fuse
Damaged BPP switch
Damaged BPA switch
Open or short in BPP circuit
Open or short in BPA circuit
Damaged PCM
Check for proper function of stoplamps and speed control operation. Follow correct Self-Test procedures, refer to Section 2 Quick Test.

P1605 - Keep Alive Memory Test Failure Indicates the PCM has experienced an internal memory test failure. However there are external items that can cause this DTC. Reprogramming
Battery terminal corrosion
Damaged PCM
KAPWR to PCM interrupt/open
Loose battery connection
If KAPWR is interrupted to the PCM, because of a battery or PCM disconnect, DTC can be generated on the first power-up.

P1633 - Keep Alive Power Voltage Too Low Indicates that the Keep Alive Power (KAPWR) circuit has experienced a power interrupt. Open KAPWR circuit
Damaged PCM
Intermittent KAPWR Circuit

P1635 - Tire/Axle Ratio Out Of Acceptable Range This Diagnostic Trouble Code (DTC) indicates the tire and axle information contained in Vehicle ID block (VID) does not match vehicle hardware. Incorrect tire size
Incorrect axle ratio
Incorrect VID configuration parameters
Using the scan tool, view the tire and axle parameters within the VID. They must match vehicle hardware.

P1636 - Inductive Signature Chip Communication Error Indicates the PCM has lost communication with the Inductive Signature Chip. PCM Damaged

P1639 - Vehicle ID Block Not Programed Or Is Corrupt This diagnostic trouble code (DTC) indicates that the vehicle ID (VID) block is not programed or the information within is corrupt. New PCM
Incorrect PCM
Incorrect VID configuration
Using an enhanced scan tool, reprogram the PCM to the most recent calibration available.

P1640 - Powertrain DTC's Available in Another Module Vehicles using a secondary Engine Control Module can request that the Powertrain Control Module illuminate the Check Engine Light when a failure occurs which affect emission. DTCs stored in a secondary module, which requested the MIL to be turned on.
Call-up PID address 0946 to determine secondary module requesting MIL illumination. Once secondary module is determined request DTCs from module.
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