My H2 cranks but has issues starting. It will start after trying a few times, problem usually happens first thing in the morning and once it’s warmed up it starts again no problem.. Idle is erratic on start up and dies out a few times before it will actually run.
Engine light is on and a number of codes came up:

P0300
P0420
P0430
P0068
P0102
P0120
P0220
P2101
P2135
P1516

Most of them are engine misfire, tac module and things related to throttle body.

I’m not sure where to even begin. Any ideas? Anyone else have this issue ? Any help would be greatly appreciated.

 

I have received a reduced engine power message, and some codes are related to catalytic converter.

 

P0300-Random cylinder misfire

P0420-Catalyst system efficiency below threshold

P0430-Catalyst system efficiency below threshold (bank 2)

P0068-MAP/MAF throttle position correlation

P0102-MAF circuit low voltage input

P0120- TPS “A” circuit malfunctioning

P0220-Throttle/ Petal Position Sensor/Switch B Circuit Malfunction

P2101-Throttle Actuator Control Motor Circuit Range/Performance

P2135-Throttle/Pedal Position Sensor/Switch "A"/"B" Voltage Correlation

P1516-Throttle Actuator Control Module Throttle Actuator Position Performance

 

With that many various codes my guess is one or more grounds are bad. Probably the one to the engine, and possibly others. Maybe a failing battery or bad connection at the battery as well.

 

Battery is new and connections have been checked. I thought it was an electrical problem with all the circuit codes. Looks like I’m going to have a fun weekend trying to figure this out. Thanks for the advice!

 

I live in Ontario and snow/rust is a big concern here. I recently had my H2 under coated. Could this in any way cause the problem I’m having ?

 

the grounds are located on the body near the body bushings so maybe it can be the undercoating if the grounds where already bad and the undercoat is now a barrier between the chassis and ground. but the engine harness grounds are bolted to the engineGrounds location

G100-Negative Battery
Cable On left front frame body mount.

G102-Engine Harness
Ground At left front side of engine block.

G102-Negative Battery
Cable At left front side of engine block.

G103 At top right rear of engine.

G103-Engine Harness
Ground At top right rear of engine.

G104 At top left rear of engine..

G105-Engine Harness
Ground At lower left side of engine.

G105-Negative Battery
Cable At lower left side of engine.

 

Thank you for ground locations! I will be sure to check them.