MALFUNCTION INDICATOR LAMP (MIL)
Most engine control system related problems that affect
emissions or driveability of the vehicle will set
a diagnostic trouble code (DTC) and illuminate the
malfunction indicator lamp.
The MIL has the following functions:
1. It notifies the driver of a problem with the fuel
system, ignition system, or emission control system
so the driver can arrange for service as soon
as possible.
2. It will display DTCs that have been stored due to
a system malfunction.
The lamp should come on when the key is in the ON
position and the engine is not running. This feature
verifies that the lamp is in proper working order.
If the lamp does not come on with the vehicle key
ON/engine OFF, repair it as soon as possible. Once
the engine is in start or run mode, the lamp should
go off. If the lamp illuminates while the engine is in
the start or run mode, there is a current diagnostic
trouble code.
SPECTRUM DIAGNOSTIC TROUBLE
CODES (DTC)
Diagnostic trouble codes are set when the Spectrum
electronic control module (ECM) runs a diagnostic
self-test and the test fails. When a DTC is set, the
ECM will illuminate the malfunction indicator lamp
(MIL) on the instrument panel and save the code in
memory. The ECM will continue to run the self-test
unless the DTC is an oxygen sensor lean, oxygen sensor
rich, or an internal ECM related DTC. If the system
continues to fail the test, the lamp will stay illuminated
and the DTC is current (ACTIVE). All DTCs
are stored as historical faults until they are cleared.
All DTCs except the ECM related DTCs will automatically
clear from memory if the DTC does not reset
within 100 consecutive engine run cycles.
While a diagnostic trouble code is current for a sensor,
the ECMmay assign a default "limp home" value
and use that value in its control algorithms. All of the
system diagnostic self-tests run continuously during
normal vehicle operation.
The diagnostic trouble codes can be read by using either
the MIL lamp or a laptop computer. Refer to
Using a Laptop Computer to Diagnose the Spectrum
System and Using a Diagnostic Jumper to Diagnose
the ECI System, located in this section. Diagnostic
trouble codes can be cleared from memory with a laptop
computer or by turning the ignition key to the
OFF position and removing the system main power
fuse (F3) for 15 seconds.
If more than one DTC is detected, always begin with
the lowest number DTC and diagnose each problem
to correction unless directed to do otherwise by the
fault chart. The DTCs are numbered in order of importance.
Having DTC 112 and DTC 122, both concerning
the oxygen sensor, is possible. By repairing
DTC 112 first, the problem causing the DTC 122 may
also be corrected.
USING A LAPTOP COMPUTER TO
DIAGNOSE THE SPECTRUM SYSTEM
Tools Required Part Number
Laptop Computer N/A
Diagnostic Software 2067944
Spectrum Special
Tools Kit
2067935
A laptop computer is the preferred tool for performing
diagnostic testing of the Spectrum system. A laptop
computer, with the system diagnostic cable and
diagnostic software, is used to read and clear Diagnostic
Trouble codes. It is also used to monitor sensor
and actuator values. The diagnostic software also
performs several special tests.

Hello

I currently have a 2006 hyster H90XMS that shows an engine light and then shuts down. How do I pull the codes on this model. I have what appears to be a six pin connector with A through F on it.

MICROPROCESSOR
SPARK TIMING SYSTEM
(MSTS)
LATE MODEL
Diagnostic Trouble Code tester.
Rinda Technologies CodeMate Tester®
(Hyster part number3071579)
I mean 2 on the edge AB
A Data
B Malfunction Indicator Lamp
(MIL)
C Diagnostic Test Terminal
E Malfunction Indicator Lamp - -

Hi Geroj

We have the following truck

Hyster
H5.00XM
K005A01774W

It has the 4 way diagnostic plug as opposed to the later versions which I believe have a 10 way diagnostic connector.

Please could you advise which two pins we need to short out in the 4 way connector to show the fault codes on the dash display.

Many Thanks

Dave

That's why I was confused. I'm not getting the code 12. Just 21 & then the 10 flashes. I'm checking into the voltage presently.

forkliftamerica,
the 10 flashes is a precursor to the error code being displayed (a self test) and are you sure its not 12 flashes?
manual says it will flash a code 12, 3 consecutive times in a row, then any fault codes stored

the code 21 is a TPS high voltage signal error

Are you responding to my message (10 fast flashes & then 21)? If so, it's Impco.

dirtbike,
what regulator is it?
spectrum or impco?

Hey, I have the exact same truck (same engine too) in my shop and the check engine light is on. When i short pins A & B I get 10 fast flashes flowed by two & then one, then another 10 fast flashes.

Does anyone know what that would be? Thanks.

I seen your video.
First Delete the error
You find here.
CARBURETED ENGINE
MANAGEMENT SYSTEM
(CEMS) H3.50-5.50XM (H70-120XM) [K005, L005
One long, four short
*not applicable*
(MAP sensor - short)
MAP (Manifold Absolute Pressure) Sensor output varies between 0 and 5 VDC as engine vacuum changes based on throttle opening and engine load.
Two long, one short
(Governor Actuator - open)
The Governor Actuator is electronically controlled by the ECU via a PWM (Pulse Width Modulated) output. Governed engine speeds and related control parameters are preset at the factory.
Two long, four short
(Idle Speed Control - short)
The Idle Speed Control is electronically controlled by the ECU via a PWM (Pulse Width Modulated) output. Engine idle speed and related control parameters are preset at the factory.

This truck running on LP or gasoline???

It runs fine and has had a tune up, and a new regulator. It does not start sometimes when hot. Has spark but no go. I ordered a scan tool.

agree w/ swoop, a good tune up is a good place to start, even 'old school', and these run pretty good even with a bad spark plug or wire off.

truck runs for a while before code sets and MIL light flashes?
i'd be willing to bet its a bad O2 sensor
those were notoriously always setting codes ;o)

but by all means get a scan tool or try the connector jumper trick first

Thanks for all the help ill give it a try.