88 code 70 help

[david sumlin]

I have a 1988 Ford Festiva and the check engine light is on. I grounded the STI and it flashed the check light 7 times. All of the flashes were evenly spaced, so I assume that it's flashing code 70. That is supposedly "vacuum switch", but that's pretty ambiguous.

Where should I start looking?

TIA

[FestYboy]

that would be code 7.

[nosuperpower]

I don't even see a code 7 in the manual. What does code 7 stand for?

[batstiva]

Assuming since you have an 89 with manual tranny that yours is carbed?
From my Haynes Manual

Carb Trouble Codes

01- Ignition coil signal

09- Coolant temperature sensor

13- MAP sensor or circuit

15- Oxygen Sensor Malfunction

17-Feedback system

18- Air bleed control valve #1

19- Air bleed control valve #2

20- Air bleed control valve #3

21- Air bleed control valve #4

22- Fuel shutoff solenoid/ circuit

28- EGR vacuum solenoid

29- EGR vacuum solenoid

31- Air Control Valve solenoid

34- Idle-up solenoid

35- Idle-up solenoid

38- EFE heater relay

70- Vacuum switch

EFI Trouble Codes

01- Ignition Diagnostic Monitor (1990-1993)

02- Crankshaft Position Sensor (1990-1993)

03- Cylinder Identification Sensor (1990-1993)

03- Camshaft Position Sensor (1994-later)

04- Crankshaft Position Sensor (1994-later)

06- Vehicle Speed Sensor

08- Airflow sensor (1990-1993)

08- Mass Air Flow Sensor (1994-later)

09- Coolant Temp Sensor

10- Intake Air Temperature Sensor

12- Throttle Position Sensor

14- Barometric Pressure Sensor

15- Oxygen Sensor

16- EGR Valve Position Sensor

17- Oxygen Sensor

25- Fuel Pressure Regulator Control Solenoid

26- Solenoid Valve (purge control)

28- EGR Control Solenoid (1994-later)

29- IAC Solenoid (1994-later)

34- IAC valve (1990-1993)

Don't really see anything here that would pertain to the neutral switch.
__________________

Per my Haynes, there is no code 7, but there is, in fact, a code 70, which would be vacuum switch. God help you on which one. Check all vac. lines for leaks, cracks, blah, blah, blah would be my first suggestion.

[WmWatt]

see photo pg 6-16 of Haynes manual. Vacuum switch is small black cyliner at top left of firewall beside #1 EGR solenoid. Haynes wiring diagram pg 12-21 says it has BLU/BLK wire and BLK ground wire. It's part of the feedback carburettor emissions control but Haynes doesn't say what it does. You may experience increased emissions and lower fuel economy?

[FB71]

First, make sure you read engine vacuum on the vac line connected to the vac switch.

If not, replace the vacuum line and recheck.

location of vac switch in first pic, diagram of switch wiring in second.

Switch has two wires.

Unplug the switch, but leave the vacuum hose connected.

Use an ohm meter to check the switch.

Key ON, engine running:
It should read open circuit (OL, or similar readout) with the engine idling (more than 3 in/Hg).

Key OFF, engine NOT running:
It should read closed circuit (less than 1 ohm) with engine off (less than 3 in/Hg).

If the switch does not work as described, replace it.

If the switch DOES work, check the black wire for a good connection to ground.

If the black wire is good, check for good continuity on the blue/black wire to pin 2J on the PCM.

[FB71]

It's part of the feedback carburettor emissions control but Haynes doesn't say what it does. You may experience increased emissions and lower fuel economy?

It detects Wide Open Throttle. Symptoms will differ, based on the failure.

[nosuperpower]

Worked with him on it and after checking that all the switches were getting juice the light went out...it looks like it was a loose wire to a switch...didn't do anything but jiggle some wires.

[FB71]

Worked with him on it and after checking that all the switches were getting juice the light went out...

apple, grape or cranberry?