Associated Equipment GM L67 User Manual

Page 27 

Enhanced parameters are additional data that can be scanned from most late-model GM vehicles.  The 
LS1 and L67/L36 support all of these listed below. 

 
Enhanced GM Parameters: (may not apply to all vehicles) 

BARO Barometric 

pressure Depends on weather.  Typically 

29-30 inches of mercury.  NOTE: 
Doesn’t work on all cars 

FTC 

Fuel trim cell 

Varies with engine conditions.  In 
general, numbers go up with 

load, except for cells 20-22, 
which may be used for open loop 
(including full throttle) 

IAC 

Idle air counts 

20-60 at warm idle to 100 while 
cruising; higher when a/c is on 

IDC1 
IDC2 

Injector duty cycle, driver’s 
side & passenger side 

1-2% at idle, up to 85% at full 
throttle 

IGNV 

Ignition volts 

12 volts or so with key on, down 
to 9.5-9.8 during starting, then 
13.5-14.5 with engine running 

IPW1 
IPW2 

Injector pulse width 

2-4 milliseconds up to 15-20 at 
higher rpm’s and full throttle 

KR 

Knock retard 

Zero to 3-4 degrees 
Ideally, should always be zero 

MAFF 

Mass air flow frequency 

2200-2300 at idle, 9000+ at full 
throttle 

MISP 

Primary misfiring cylinder 

1-8 if misfires present 

MISR 

Revolutions with misfires 

0-10 revs is common; more than 
that may indicate problem 

TFT Transmission 

Fluid 

Temperature 

Ambient to 200 deg F or so.  
Above 225 and the tranny fluid 
starts to deteriorate. 

TPSV 

Throttle position sensor 
voltage 

0-5Volts; typically 0.5 volts at 
idle & 4.5 at full throttle