Your Vehicle: 2001 Ford Escort ZX2 L4-2.0L DOHC VIN 3
 
Vehicle » Powertrain Management » Computers and Control Systems » Testing and Inspection » Pinpoint Tests » HM: Secondary Air Injection (AIR) System - Pinpoint Test  
 
 
  HM: Secondary Air Injection (AIR) System - Pinpoint Test  
 

HM: Secondary Air Injection (AIR) System

HM: Introduction See: HM: Secondary Air Injection (AIR) System - Introduction

HM1 DTC P0412: CHECK B+ VOLTAGE TO SOLID STATE RELAY

  • Disconnect SSR.
  • Key on, engine off.
  • Measure voltage of B+ circuit at SSR harness connector and battery negative post.

Is voltage greater than 10.5 volts?
Yes

  • Supplied voltage is OK, GO to HM2

.

No

  • GO to HM6

.

HM2 CHECK EAIR CIRCUIT FOR OPEN IN HARNESS

  • Key off.
  • Disconnect AIR bypass solenoid.
  • Remove Secondary Air Injection System dedicated fuse temporarily.
  • Disconnect PCM.
  • Measure resistance of EAIR circuit between PCM harness connector pin and SSR harness connector and AIR bypass harness connector.

Is resistance less than 5.0 ohms?
Yes

  • GO to HM3

.

No

  • REPAIR open circuit.

HM3 CHECK EAIR CIRCUIT FOR SHORT TO POWER AND GROUND WITH DISCONNECTED AIR BYPASS SOLENOID

  • Measure resistance between EAIR and VPWR circuits at the PCM harness connector.
  • Measure resistance between EAIR at the PCM harness connector and battery negative post.

Is each resistance greater than 10,000 ohms?
Yes

  • The EAIR harness is OK. GO to HM4

.

No

  • REPAIR short circuit.

HM4 CHECK AIR BYPASS SOLENOID RESISTANCE

  • Disconnect AIR bypass solenoid harness connector.
  • Measure AIR bypass solenoid resistance.

Is resistance between 50 and 100 ohms?
Yes

  • GO to HM5

.

No

  • REPLACE AIR bypass solenoid.

HM5 CHECK EAIR CIRCUIT FOR SHORT TO POWER AND GROUND WITH SOLID STATE RELAY RECONNECTED

  • AIR bypass solenoid disconnected.
  • Reconnect solid state relay.
  • Measure resistance of EAIR circuit between VPWR and PWR GND circuits at the PCM harness connector.

Is each resistance greater than 10,000 ohms?
Yes

  • If DTC P0411 is present:
  • GO to HM9

.

  • All others:
  • GO to HM16

.

No

  • REPLACE solid state relay.

HM6 CHECK B+ CIRCUIT FOR OPEN IN HARNESS

  • Measure resistance of B+ circuit between solid state relay harness connector and Secondary Air Injection System dedicated fuse.

Is resistance less than 5.0 ohms?
Yes

  • CHECK VPWR circuit for short to ground. REPLACE fuse. GO to HM8

to check electric AIR pump. RECONNECT solid state relay.

No

  • REPAIR open circuit. RECONNECT solid state relay and fuse.

HM7 DTC P0411: VISUALLY INSPECT ELECTRIC AIR PUMP HOSES AND AIR SILENCER (9H467)

  • Visually inspect electric AIR pump hoses from the electric AIR pump to the AIR diverter valves.
  • Visually inspect for damaged exhaust system.
  • Inspect air hose for cracks, binding, obstructions, water or ice.
  • Inspect Air silencer (9H467) for obstructions.

Are electric AIR pump hoses and Air silencer (9H467)OK?
Yes

  • GO to HM8

.

No

  • DRAIN all water from hoses or REPLACE damaged parts.

HM8 CHECK ELECTRIC AIR PUMP OPERATION

  • Key on, engine off.
  • Enter output test mode

Does the pump run?
Yes

  • KEY OFF. GO to HM17

to check electric AIR pump for
water contamination.

No

.
If OK, GO to HM13
.
CAUTION: RUNNING OUTPUT TEST MODE LONGER THAN TWO MINUTES MAY OVERHEAT/DAMAGE AIR PUMP.

HM9 CHECK FOR VACUUM AT AIR DIVERTER VALVES

  • Connect a vacuum gauge to the control vacuum hose at the AIR diverter valve(s).
  • Apply 53kPa (16in-HG) of vacuum at the intake manifold side of the AIR bypass solenoid vacuum supply hose.
  • Key on, engine off.
  • Enter output test mode

Is vacuum present at the AIR Diverter valve(s)?
Yes

  • GO to HM10

.

No

  • GO to HM32

.

HM10 CHECK AIR DIVERTER VALVE(S) INTEGRITY

  

CAUTION: Caution must be observed while performing this test.
Note: On a two valve system make sure that air is flowing from both valves.

Is air present from the AIR diverter valve(s)?
Yes

to the exhaust manifold(s). If OK, GO to HM11
.

No

  • KEY OFF. INSPECT hose from electric AIR pump to AIR diverter

valve(s). If OK, REPLACE the appropriate AIR diverter valve(s).

HM11 CHECK MANIFOLD VACUUM WITH EXHAUST MANIFOLD DISCONNECTED FOR INDICATION OF A RESTRICTION

Note: An intake manifold gasket leak can also cause the vacuum gauge needle to remain well below the normal range.

  • Disconnect exhaust system immediately after the exhaust manifold.
  • Observe the rate of speed the vacuum gauge needle rises, while maintaining 2000 rpm.

Note: The rate of speed the vacuum gauge needle rises to the normal range is slower on a restricted system than on a non-restricted system as the increased rpm is maintained.
Did the vacuum needle QUICKLY rise above 54 kPa (16 inches-Hg) with the engine speed at 2000 rpm?
Yes

  • The exhaust system restriction is downstream of the exhaust

manifold. RECONNECT exhaust system at exhaust manifold. GO to HM12
.

No

  • A restriction is present in the exhaust manifold. INSPECT each

exhaust port for casting flash/restrictions by dropping a length of chain
into it (NOTE: Do not use a wire or lamp to check the ports. The restriction
can be small enough for both to pass through, but large enough to cause excessive
back-pressure at high engine rpm.). REPLACE the exhaust manifold if unable
to remove the casting flash/restriction.

HM12 CHECK MANIFOLD VACUUM WITH MUFFLER/TAILPIPE ASSEMBLY DISCONNECTED FOR INDICATION OF A RESTRICTION

  • Disconnect muffler/tailpipe assembly from the catalytic converter.
  • GO to HM11 to repeat the vacuum measurement.

Did the vacuum needle QUICKLY rise above 54 kPa (16 inches-Hg) with the engine speed at 2000 rpm?
Yes

  • There is a restriction in the muffler/tailpipe assembly. REPLACE

the muffler/tailpipe assembly.

No

catalytic converter. INSPECT the muffler to be certain converter debris has
not entered.

HM13 CHECK VOLTAGE ON EAIR MONITOR CIRCUIT

  • Disconnect electric AIR pump.
  • Key on, engine off.
  • Enter output test mode.
  • Measure voltage of EAIR monitor circuit between electric AIR pump harness connector and battery negative post.

Is voltage greater than 10.5 volts?
Yes

  • GO to HM15

.

No

  • GO to HM14

.

HM14 CHECK ELECTRIC AIR PUMP GROUND FOR OPEN IN HARNESS

  • Measure resistance of EAP ground circuit between electric AIR pump harness connector and battery negative post.

Is resistance less than 5 ohms?
Yes

  • GO to HM21

.

No

  • REPAIR open circuit.

HM15 CHECK AIR HOSE TO ELECTRIC AIR PUMP

  • Disconnect inlet air hose.
  • Visually inspect inlet air hose for binding, obstructions, water or ice to the electric AIR pump.

Is the hose integrity or orientation OK?
Yes

  • GO to HM17

.

No

  • DRAIN all water from air hose. REPLACE or RE-ORIENT hose as

appropriate. GO to HM17
.

HM16 CHECK SOLID STATE RELAY OUTPUT

  • Reconnect AIR bypass solenoid.
  • Connect PCM.
  • Key on, engine off.
  • Enter output test mode.
  • Access AIR PID.
  • Access AIRM PID.
  • Compare AIR and AIRM PIDs.

Were both PIDs on?
Yes

  • REPLACE solid state relay.

No

  1. If no problem is found, REPLACE PCM (REFER to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

HM17 CHECK AIR PUMP FOR WATER

Note: Water ingested in the electric AIR pump will reduce the life of the pump.

  • Disconnect electric AIR pump connector and air hoses.
  • Carefully tilt electric AIR pump in various positions to verify if any water is present.

Is any water present?
Yes

  • REPLACE electric AIR pump.

No

  • If fuse was replaced, GO to HM6

, Testing is complete.

  • All others, GO to HM9

.

HM19 DTC P1413: CHECK B+ CIRCUIT VOLTAGE TO SOLID STATE RELAY

  • Disconnect solid state relay.
  • Key on.
  • Measure voltage of B+ circuit between solid state relay harness connector and chassis ground.

Is voltage greater than 10.5 volts?
Yes

  • GO to HM20

.

No

  • GO to HM26

.

HM20 CHECK FOR VPWR TO SOLID STATE RELAY

  • Key on, engine off.
  • Measure VPWR circuit voltage at the solid state relay harness connector.

Is voltage greater than 10.5 volts?
Yes

  • GO to HM21

.

No

  • For LS6

:

.

  • All others

:

  • REPAIR open VPWR circuit between the solid state relay and Electronic

Engine Control power relay.

HM21 CHECK VOLTAGE ON EAIR MONITOR CIRCUIT

  • Reconnect solid state relay.
  • Disconnect electric AIR pump.
  • Key on, engine off.
  • Enter output test mode.
  • Access AIRM PID.

Is PID on?
Yes

  • GO to HM25
  1. REMAIN in output test mode.

No

  • If DTC P0411 is present, REPLACE electric AIR pump. GO to HM22
  1. REMAIN in output test mode.

HM22 CHECK EAIR MONITOR VOLTAGE TO PCM

  • Key on, engine off.
  • Access AIRM PID.

Is PID on?
Yes

No

  • GO to HM23

.

HM23 CHECK EAIR DRIVER AND EAIR MONITOR CIRCUIT FOR OPEN IN HARNESS

  • Disconnect solid state relay.
  • Measure resistance of EAIR driver circuit between PCM harness connector and solid state relay harness connector.
  • Measure resistance of EAIR monitor circuit between PCM harness connector and solid state relay harness connector.
  • Measure resistance of EAIR monitor circuit between the solid state relay harness connector and the electric AIR pump harness connector.

Is each resistance less than 5.0 ohms?
Yes

  • GO to HM24

.

No

  • REPAIR open circuit.

HM24 CHECK EAIR MONITOR CIRCUIT FOR SHORT TO GROUND IN HARNESS

  • Measure resistance between EAIR monitor and PWR GND circuit at the PCM harness connector.

Is resistance greater than 10,000 ohms?
Yes

  • REPLACE solid state relay.

No

  • REPAIR short circuit.

HM25 CHECK EAIR MONITOR VOLTAGE TO PCM

  • Reconnect electric AIR pump.
  • Reconnect PCM.
  • Key on, engine off.
  • Access AIRM PID.

Is PID on?
Yes

No

  • REPAIR open EAIR circuit.

HM26 CHECK B+ CIRCUIT FOR OPEN IN HARNESS

  • Measure resistance of B+ circuit between solid state relay harness connector and dedicated fuse B+ circuit.

Is resistance less than 5 ohms?
Yes

  • REPLACE solid state relay dedicated fuse.

No

  • REPAIR open circuit.

HM27 DTC P1414: CHECK EAIR MONITOR CIRCUIT FOR OPEN IN HARNESS

  • Disconnect solid state relay.
  • Disconnect PCM.
  • Disconnect electric AIR pump.
  • Measure resistance of EAIR monitor circuit between PCM harness connector and electric AIR pump harness connector.

Is resistance less than 5 ohms?
Yes

  • GO to HM28

.

No

  • REPAIR open circuit.

HM28 CHECK ELECTRIC AIR PUMP FOR OPEN

  • Measure electric AIR pump resistance.

Is resistance between 0.5-5.0 ohms?
Yes

  • GO to HM29

.

No

  • REPLACE electric AIR pump.

HM29 CHECK EAIR MONITOR CIRCUIT FOR SHORT TO POWER IN HARNESS

  • Key on.
  • Measure voltage between PCM harness connector and chassis ground.

Is voltage greater than 10.5 volts?
Yes

  • REPAIR short circuit.

No

  • EAIR Monitor circuit is OK. GO to HM30

.

HM30 CHECK SOLID STATE RELAY OUTPUT

  • Reconnect AIR bypass solenoid.
  • Connect PCM.
  • Key on, engine off.
  • Enter output test mode.
  • Access AIR PID.
  • Access AIRM PID.
  • Compare AIR and AIRM PIDs.

Were both PIDs on?
Yes

  • REPLACE solid state relay.

No

HM32 CHECK VACUUM HOSE INTEGRITY

  • Key off.
  • Check vacuum hose between Intake manifold and AIR diverter valve(s).
  • Check for blockage and restrictions.
  • Check for leaks and cracks.
  • Check for kinks or disconnects.

Are the above checks OK?
Yes

  • GO to HM33

.

No

  • REPLACE damaged vacuum hose.

HM33 CHECK AIR BYPASS SOLENOID ELECTRICAL OPERATION

  • Key on, engine off.
  • Access Output Test Mode.
  • Disconnect AIR bypass solenoid.
  • Connect digital multimeter to AIR bypass solenoid vehicle harness connector.
  • Turn the outputs on, then turn outputs off while observing digital multimeter.

Does EAIR circuit voltage cycle greater than 0.5 volt?
Yes

  • REMAIN in Output Test Mode. GO to HM34

.

No

  • Key off. GO to HM35

.

HM34 CHECK AIR BYPASS SOLENOID FOR MECHANICAL OPERATION

  • Reconnect AIR bypass solenoid.
  • Disconnect source vacuum hose from AIR bypass solenoid.
  • Apply 53 kPa (16 in-Hg) of vacuum to source side of AIR bypass solenoid.
  • Turn the outputs on, then turn outputs off.

Was vacuum released?
Yes

  • REPAIR vacuum hose from manifold vacuum tree to AIR bypass solenoid.

If OK, GO to Z2 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\Z: Intermittent - Pinpoint Test
.

No

  • REPLACE AIR bypass solenoid.

HM35 CHECK AIR BYPASS SOLENOID RESISTANCE

  • Disconnect AIR bypass solenoid harness connector.
  • Measure AIR bypass solenoid resistance.

Is resistance between 50 and 100 ohms?
Yes

  • GO to HM36

.

No

  • REPLACE AIR bypass solenoid.

HM36 CHECK VPWR CIRCUIT FOR OPEN IN HARNESS

  • Key on, engine off.
  • Measure VPWR circuit voltage at the AIR bypass solenoid harness connector.

Is voltage greater than 10.5 volts?
Yes

  • GO to HM37

.

No

  • REPAIR open VPWR circuit (and dedicated fuse on LS6).

HM37 CHECK EAIR CIRCUIT FOR OPEN IN HARNESS

  • Disconnect solid state relay.
  • Disconnect PCM.
  • Measure resistance of EAIR circuit between PCM harness connector and the AIR bypass solenoid harness connector and at the solid state relay harness connector.

Is resistance less than 5.0 ohms?
Yes

  • GO to HM38

.

No

  • REPAIR open EAIR circuit.

HM38 CHECK EAIR CIRCUIT FOR SHORT TO GROUND IN HARNESS

  • Measure resistance between EAIR and PWR GND circuits at the PCM harness connector.

Is resistance greater than 10,000 ohms?
Yes

  • GO to HM39

.

No

  • REPAIR short to ground.

HM39 CHECK EAIR CIRCUIT FOR SHORT TO POWER IN HARNESS

  • Measure resistance between EAIR and PWR GND circuits at the PCM harness connector.

Is each resistance greater than 10,000 ohms?
Yes

No

  • REPAIR short to power.